Phosphacycle compound and process for production thereof

ABSTRACT

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The invention relates to oligomerization of olefins, such as ethylene,to higher olefins, such as a mixture of 1-hexene and 1-octene, using acatalyst system that comprises a) a source of chromium b) one or moreactivators and c) a phosphacycle-containing ligating compound.Additionally, the invention relates to a phosphacycle-containingligating compound and a process for preparing said compound.

Numerous improvements in the ligating compounds for catalyst systemsused in olefin oligomerization have been disclosed. However, problemsstill remain with catalyst efficiency, catalyst selectivity, formationof polymer byproduct, and deactivation of the catalyst under hightemperature conditions. It would be advantageous to discover a catalystsystem able to produce olefin oligomers with higher catalyst efficiency,higher catalyst selectivity, and less polymer byproduct formation.

It is believed that the rate of formation of C₁₀₊ oligomers is relatedto the concentration of 1-hexene and/or 1-octene that are present in thereaction vessel in which the oligomerization occurs, such as disclosedin US Patent Application Publication 2015-0284303. Such reactions thatmaximize the concentration of 1-hexene and 1-octene in the reactor haveprovided poor product selectivity. In particular, the production oflarger amounts of C₁₀₊ oligomers has been observed under conditions thatprovide for a higher concentration of 1-hexene and/or 1-octene. Theperformance of chromium-bridged diphosphine catalysts is typicallytemperature dependent. The prior art generally discloses preferredoperating temperatures of from 50 to 150° C., especially from 60 to 90°C. Very high activities (of greater than 2×10⁶ grains of product pergram of catalyst per hour) have been reported at this temperature range.However, simple batch experiments have shown that this high activity,which leads to a high concentration of 1-hexene and 1-octene in thereactor, is also associated with a decrease in product selectivity—inparticular, the production of a higher amount of C₁₀₊ oligomers has beenobserved. Batch experiments have shown that product selectivity may beimproved by lowering the reaction temperature, but a loweroligomerization temperature is not “sufficient” to minimize the C₁₀₊fraction.

Diphosphine ligands having a dioxyphosphacyclic group have been taughtin WO2013168102 as being useful for the tetramerization of ethylene.

Surprisingly, it has been found that catalyst systems based on certainphosphacyclic ligating compounds desirably provide reduced polymerformation, and, in many cases, improved catalyst efficiency andselectivity.

SUMMARY OF THE INVENTION

The invention provides a process for selectively oligomerizing an olefincomprising contacting at least one olefin with a catalyst system underolefin oligomerization conditions sufficient to convert at least aportion of the at least one olefin to at least one oligomer of the atleast one olefin, the catalyst system comprising, a) a source ofchromium, b) one or more activators, and c) at least onephosphacycle-containing ligating compound R₁R₂P—Y—X₁R₃(R₄)_(m)represented as:

wherein:P is phosphorus; X₁ is selected from nitrogen, phosphorus, oxygen, orsulfur; each of R₁ and R₂ is independently a substituted orunsubstituted hydrocarbon derivative, a substituted or unsubstitutedheterohydrocarbon derivative, or a substituted or unsubstitutedheteroatom group having from one to 50 non-hydrogen atoms; m is 0 or 1;R₁ and R₂ are linked together to form a divalent moiety represented as

which together with P forms a cyclic structure (phosphacycle) containingfrom 3 to 10 ring atoms; each of R₃ and R₄ is independently hydrogen,halogen, a substituted or unsubstituted hydrocarbon derivative, asubstituted or unsubstituted heterohydrocarbon derivative, or asubstituted or unsubstituted heteroatom group having from one to 50non-hydrogen atoms; R₃ and R₄ are optionally linked together to form adivalent moiety represented as

wherein the optional character of the linkage is depicted by a dashedconnection, which together with X₁ forms a cyclic structure containingfrom 3 to 10 ring atoms; Y, optionally linked together with one or moreof R₁, R₂, R₃, or R₄ to form cyclic structures containing from 4 to 10ring atoms, as represented by:

wherein the optional character of the linkages is depicted by a dashedconnection, is a divalent linking group [L(R₅)_(q)]_(p) between P and X₁containing from one to 50 non-hydrogen atoms; [L(R₅)_(q)]_(p) isrepresented by:

wherein each L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur; p is an integer number from 1 to 6, preferably from 1 to 4; R₅is independently hydrogen, halogen, substituted or unsubstitutedhydrocarbon derivative, substituted or unsubstituted heterohydrocarbonderivative, or a substituted or unsubstituted heteroatom group; q is 0,1, or 2; provided that the [L]_(p) subunit of the divalent linking group[L(R₅)_(q)]_(p) does not comprise an amidine (N—C═N) group; furtherprovided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; still further preferably provided that oneor two phosphacycles comprising P or X₁, preferably comprising P, R₁,and R₂, or comprising X₁, R₃, and R₁, contain no P—N, P—O, or P—S bondswithin the ring part of the phosphacycle; two or more R₅ groupsindependently are linked together with at least one L atom to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; two R₅ groups attached to the same L atom may beoptionally linked together to form a cyclic structure that contains from3 to 10 ring atoms, preferably from 3 to 7 ring atoms; from two to ten,preferably from two to six, independently selected ligating compoundsmay be optionally linked together via their respective independentlyselected Y, R₁, R₂, R₃, R₄ or R₅ groups to form a poly(ligatingcompound) species. Preferably at least one, preferably two,phosphacycles do not contain more than one carbon-carbon unsaturatedbond in each phosphacycle, preferably not more than one unsaturated bondin each phosphacycle.

Another embodiment of the invention provides a catalyst system for theoligomerization of olefins, the catalyst system comprising, a) a sourceof chromium, b) one or more activators, and c) at least onephosphacycle-containing ligating compound, as described herein.

Another embodiment of the invention provides a process to produce acatalyst system for the oligomerization of olefins, the catalyst systemcomprising, a) a source of chromium, b) one or more activators, and c)at least one phosphacycle-containing ligating compound, as describedherein.

Another embodiment of the invention provides a phosphacycle-containingligating compound-chromium complex comprising a) a source of chromium,and b) a phosphacycle-containing ligating compound, as described herein.

Another embodiment of the invention provides a process to produce aphosphacycle-containing ligating compound-chromium complex comprising a)a source of chromium, and b) a phosphacycle-containing ligatingcompound, as described herein.

Another embodiment of the invention provides a phosphacycle-containingligating compound as described herein.

Another embodiment of the invention provides a process to produce aphosphacycle-containing ligating compound as described herein.

Another embodiment of the invention provides a catalyst system for theoligomerization of olefins, the catalyst system comprising, a) a sourceof chromium, b) one or more activators, and c) at least onepoly(ligating compound) species, as described herein.

Another embodiment of the invention provides a process to produce acatalyst system for the oligomerization of olefins, the catalyst systemcomprising, a) a source of chromium, b) one or more activators, and c)at least one poly(ligating compound) species, as described herein.

Another embodiment of the invention provides a poly(ligatingcompound-chromium complex) species comprising a) a source of chromium,and b) a poly(ligating compound) species, as described herein.

Another embodiment of the invention provides a process to produce apoly(ligating compound-chromium complex) species comprising a) a sourceof chromium, and b) a poly(ligating compound) species, as describedherein.

Another embodiment of the invention provides a poly(ligating compound)species as described herein.

Another embodiment of the invention provides a process to produce apoly(ligating compound) species as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Crystal structure oftrichloro[1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene](tetrahydrofuran)chromium, (3), drawn with 50% thermal ellipsoidprobability. Hydrogen atoms are omitted for clarity. Carbon atoms arerepresented by gray thermal ellipsoids.

FIG. 1. Crystal structure ofdi-μ₂-chlorotetrachlorobis[[1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene]]dichromium,(4), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

FIG. 2. Crystal structure oftrichloro[1,2-bis[(2R,5R)-2,5-diethylphospholano]benzene](tetrahydrofuran)chromium,(6), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

FIG. 3. Crystal structure oftrichloro[1,2-bis[(2S,5S)-2,5-di-(1-methylethyl)phospholano]benzene](tetrahydrofuran)chromium,(8), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

FIG. 4. Crystal structure oftrichloro[1,2-bis[(2R,5R)-2,5-diethylphospholano]ethane](tetrahydrofuran)chromium,(12), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

FIG. 5. Crystal structure oftrichloro[N,N-bis(diphenylphosphino)-N-isopropylamine](tetrahydrofuran)chromium.toluene,(14), drawn with 50% thermal ellipsoid probability. Hydrogen atoms andthe solvate toluene molecule are omitted for clarity. Carbon atoms arerepresented by gray thermal ellipsoids.

FIG. 6. Crystal structure of(2S,5S)—N-butyl-N-(2,5-diphenylphospholan-1-yl)-N-diphenylphosphinoamine,(17), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

FIG. 8. Crystal structure ofdi-(μ₂-chlorotetrachlorobis[(2S,5S)—N-butyl-N-(2,5-diphenylphospholan-1-yl)-N-diphenylphosphinoamide]dichromium,(19), drawn with 50% thermal ellipsoid probability. Hydrogen atoms areomitted for clarity. Carbon atoms are represented by gray thermalellipsoids.

DETAILED DESCRIPTION OF THE INVENTION General Definitions

As used herein, “ring atom” means an atom that together with at leasttwo other atoms forms a ring or cyclic structure.

As used herein, the term “hydrocarbon derivative”, e.g., hydrocarbonderivative, substituted hydrocarbon derivative, hydrocarbonderivative-containing, refers to a group of compounds consisting ofcarbon and hydrogen only. Specifically, “hydrocarbon derivative” refersto the group consisting of hydrocarbyl, hydrocarbylene,hydrocarbylidene, and hydrocarbylidyne, the terms “hydrocarbyl”,“hydrocarbylene”, “hydrocarbylidene”, and “hydrocarbylidyne” having thesame meaning as established by the IUPAC (International Union of Pureand Applied Chemistry): Hydrocarbyl groups are univalent groups formedby removing a hydrogen atom from a hydrocarbon, e.g., methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, cyclohexyl,cyclohexylmethyl, phenyl, benzyl, naphthyl. Hydrocarbylene groups aredivalent groups formed by removing two hydrogen atoms from ahydrocarbon, the free valencies of which are not engaged in a doublebond, e.g., 1,2-phenylene, —CH₂CH₂CH₂— (propane-1,3-diyl), —CH₂—(methylene), C₆H₃C₆H₅ (5-phenyl-1,3-phenylenediyl. Hydrocarbylidenegroups are divalent groups formed by removing two hydrogen atoms fromthe same carbon atom of a hydrocarbon, the free valencies of which areengaged in a double bond, e.g., CH₃CH═ (ethylidene), C₆H₅CH═(benzylidene). Hydrocarbylidyne groups are trivalent groups formed byremoving three hydrogen atoms from the same carbon atom of ahydrocarbon, the free valencies of which are engaged in a triple bond,e.g., CH₃CH₂O (propylidyne), C₆H₅C≡ (benzylidyne). The term “hydrocarbonderivative” as used herein refers to hydrocarbon derivative radicalscontaining 1 to 50 carbon atoms, preferably 1 to 30 carbon atoms, morepreferably 1 to 20 carbon atoms, most preferably 1 to 16 carbon atoms,including branched or unbranched, cyclic or acyclic, saturated orunsaturated species, such as alkyl groups, alkenyl groups, alkynylgroups, aryl groups, arylalkyl groups, cycloalkyl groups, alkanediylgroups, alkylenediyl groups, arylenediyl groups, alkylidene groups, andthe like.

As used herein, the term “heterohydrocarbon derivative”, e.g.,heterohydrocarbon derivative, substituted heterohydrocarbon derivative,heterohydrocarbon derivative-containing, refers to a hydrocarbonderivative as defined above in which at least one carbon atom and,optionally, its attached hydrogen atoms in the hydrocarbon derivativeare replaced with at least one heteroatom. Specifically,“heterohydrocarbon derivative” refers to the group consisting ofheterohydrocarbyl, heterohydrocarbylene, heterohydrocarbylidene, andheterohydrocarbylidyne, the terms “heterohydrocarbyl”,“heterohydrocarbylene”, “heterohydrocarbylidene”, and“heterohydrocarbylidyne” having the same meaning as defined above fordie respective hydrocarbon derivatives, e.g., hydrocarbyl,hydrocarbylene, hydrocarbylidene, and hydrocarbylidyne, wherein at leastone carbon atom and, optionally, its attached hydrogen atoms in thehydrocarbon derivative is replaced with at least one hetcroatom.Heterohydrocarbyl groups are univalent groups formed by removing atleast one carbon atom and, optionally, its attached hydrogen atoms froma hydrocarbyl group, and replacing it with at least one heteroatom,e.g., CH₃O— (methoxy), CF₃— (trifluoromethyl), CH₃CH₂NH— (ethylamino),(CH₃CH₂)₂NC₆H₄— (dimethylaminophenyl), C₆H₅OC₆H₄CH₂— (phenoxybenzyl),CH₃OCH₂CH₂OCH₂— (methoxyethoxymethyl), C₅H₄N— (pyridyl).

Heterohydrocarbylene groups are divalent groups formed by removing atleast one carbon atom and, optionally, its attached hydrogen atoms froma hydrocarbylene group and replacing it with at least one heteroatom,the free valencies of which heterohydrocarbylene group are not engagedin a double bond, e.g., —CH₂CH₂N(CH₃)CH₂CH₂—(methylaminodi-(2,1-ethane)diyl), —CH₂CH₂OCH₂CH₂—(oxydi-(2,1-ethane)diyl), —CH₂CH₂CH₂CH₂O— (4-butaneyl-1-oxy), —OCH₂CH₂O—(1,2-ethanediylbis(oxy)),—CH₂CH(CF₃)CH₂-(2-trifluoromethyl-1,3-propanediyl),—CH₂COCH₂CH₂-(2-oxo-1,4-butanediyl). Heterohydrocarbylidene groups aredivalent groups formed by removing at least one carbon atom and,optionally, its attached hydrogen atoms from a hydrocarbylidene groupand replacing it with at least one heteroatom, the free valencies ofwhich heterohydrocarbylidene group are engaged in a double bond, e.g.,CH₃₀CH₂CH═ (methoxyethylidene), C₆H₃Cl₂CH═ (dichlorobenzyiidene),(CH₃)₂NCH═ (dimethylaminomethylidene), C₆H₅CH₂N═ (benzylimine).Heterohydrocarbylidyne groups are trivalent groups formed by removing atleast one carbon atom and, optionally, its attached hydrogen atoms froma hydrocarbylidyne group and replacing it with at least one heteroatom,the free valencies of which heterohydrocarbylidyne group are engaged ina triple bond, e.g., CH₃OCH₂C≡ (2-methoxyethylidyne), (CH₃)₂NC₆H₄C═(dimethylaminobenzylidyne).

More generally, the modifiers “hetero” and “heteroatom-containing”,e.g., “heteroalkyl”, “heteroaryl”, “heterohydrocarbon derivative”,“heteroatom-containing hydrocarbyl group”, refer to a molecule ormolecular fragment in which one or more carbon atoms and, optionally,its attached hydrogen atoms are replaced with a heteroatom. Thus, forexample, the term “heteroalkyl” refers to an alkyl substituent thatcontains a heteroatom. When the term “heteroatom-containing” introducesa list of possible heteroatom-containing groups, it is intended that theterm apply to every member of that group. That is, the phrase“heteroatom-containing alkyl, alkenyl, alkynyl, aryl, and arylalkyl” isto be interpreted as “heteroatom-containing alkyl, heteroatom-containingalkenyl, heteroatom-containing alkynyl, heteroatom-containing aryl, andheteroatom-containing arylalkyl.” The free valence of theheterohydrocarbon derivative may reside oil a heteroatom, as in methoxy(CH₃O—), diethylamino ((CH₃CH₂)₂N—), or butylthio (CH₃CH₂CH₂CH₂S—), orit may reside on a carbon atom, as in N,N-dimethylaminoethyl((CH₃)₂NCH₂CH₂—), pyridylmethyl (C₅H₄NCH₂—), or methoxyethyl(CH₃OCH₂CH₂—). The term “heterohydrocarbon derivative” as used hereinrefers to heterohydrocarbon derivative radicals containing 1 to 50carbon atoms, preferably 1 to 30 carbon atoms, more preferably 1 to 20carbon atoms, most preferably 1 to 16 carbon atoms, including branchedor unbranched, cyclic or acyclic, saturated or unsaturated species,e.g., heterohydrocarbyl groups, heteroalkyl groups, heteroalkenylgroups, and heteroaryl groups.

The term “heteroatom group” refers to an atom or molecular fragmentcomprising at least one heteroatom and no carbon atoms, for example,nitro (—NO₂), oxo (═O), and sulfonic acid (—SO₃H) groups. The heteroatomgroup contains from 1 to 40 atoms, preferably 1 to 10 atoms, morepreferably 1 to 6 atoms.

As used herein, heteroatoms may be selected from the group consisting ofB, Si, Ge, N, P, As, Sb, Bi, O, S, Se, F, Cl, Br, I, and transitionmetals, preferably from the group consisting of B, Si, Ge, N, P, O, S,Se, F, Cl, Br, I, and transition metals.

As used herein, the term “substituted”, e.g., “substituted hydrocarbonderivative”, “substituted heterohydrocarbon derivative”, “substitutedhydrocarbyl,” “substituted heterohydrocarbyl”, “substituted aryl,”“substituted arylalkyl.” “substituted alkyl,” means that in the group inquestion (e.g., the hydrocarbon derivative, heterohydrocarbonderivative, hydrocarbyl, heterohydrocarbyl, aryl, arylalkyl, alkyl, orother moiety that follows the term “substituted”), at least one hydrogenatom bound to a carbon atom or to a heteroatom is replaced with one ormore heteroatoms, unless another type of substitution is specificallystated, such as “alkyl-substituted” or “substituted by aryl”. When theterm “substituted” introduces a list of possible substituted groups, itis intended that the term apply to every member of that group. That is,the phrase “substituted alkyl, alkenyl, alkynyl, aryl, and arylalkyl” isto be interpreted as “substituted alkyl, substituted alkenyl,substituted alkynyl, substituted aryl, and substituted arylalkyl.”Similarly, “optionally substituted alkyl, alkenyl, alkynyl, arylalkyl”is to be interpreted as “optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, and optionallysubstituted arylalkyl.”

There is some overlap in terms of the definitions of “substitutedhydrocarbon derivative” and “heterohydrocarbon derivative”. For example,‘2-fluoroethyl’ is the ‘ethyl’ hydrocarbon derivative substituted withone fluorine atom. At the same time it may be classified as aheterohydrocarbon derivative formed by taking a propyl group (CH₃CH₂CH₂)and replacing the methyl (CH₃) carbon and its attached hydrogen atomswith a fluorine heteroatom. In either case, it will be clear to oneskilled in the art that either classification is operative. In anotherexample, ‘pyridylmethyl’ is the ‘methyl’ hydrocarbon derivativesubstituted with a pyridyl group. At the same time it may be classifiedas a heterohydrocarbon derivative formed by taking a benzyl group(C₆H₅CH₂) and replacing one of the ring carbons and its attachedhydrogen atom with a nitrogen heteroatom. In either case, it will beclear to one skilled in the art that either classification is operative.

The term “alkyl” as used herein refers to a branched or unbranched,cyclic or acyclic saturated hydrocarbyl radical typically, although notnecessarily, containing 1 to 50 carbon atoms, more preferably 1 to 25carbon atoms, most preferably 1 to 16 carbon atoms, e.g., methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl,hexyl, octyl, decyl, as well as cycloalkyl groups, e.g., cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, andcyclohexylethyl.

The term “alkenyl” as used herein refers to a branched or unbranched,cyclic or acyclic hydrocarbyl radical containing at least one doablebond and typically, although not necessarily, containing 2 to 50 carbonatoms, more preferably 2 to 25 carbon atoms, most preferably 2 to 16carbon atoms, e.g., ethenyl, n-propenyl, isopropenyl, n-butenyl,isobutenyl, 4-octenyl, 2-decenyl, cyclopentenyl, cyclopentadienyl,cyclohexenyl, and cyclohexadienyl.

The term “olefin” as used herein refers to branched or unbranchedacyclic or cyclic hydrocarbons having one or more carbon-carbon doublebonds, apart from the formal ones in aromatic compounds and typically,although not necessarily, containing 2 to 50 carbon atoms, morepreferably 2 to 25 carbon atoms, most preferably 2 to 16 carbon atoms,e.g., ethene (ethylene), propene (propylene), 1-butene, 2-butene,isobutene, 1-hexene, 3-hexene, 1-octene, 2-decene, cyclopentene,cyclopentadiene, cyclohexene, and cyclohexadiene.

Under the term “α-olefins” as used herein refers olefins with terminaldouble bonds and typically, although not necessarily, containing 2 to 50carbon atoms, more preferably 2 to 25 carbon atoms, most preferably 2 to16 carbon atoms, e.g., ethylene, propylene, 1-butene, 1-pentene,1-hexene, 1-heptene, 1-octene, and 1-decene.

The term “alkynyl” as used herein refers to a branched or unbranched,cyclic or acyclic hydrocarbon radical containing at least one triplebond and typically, although not necessarily, containing 2 to 50 carbonatoms, more preferably 2 to 25 carbon atoms, most preferably 2 to 16carbon atoms, e.g., ethynyl, n-propynyl, isopropynyl, n-2-butynyl,isobutynyl, octynyl, 3-decynyl, cyclooctynyl.

The term “aromatic” is used in its usual sense, including unsaturationthat is essentially delocalized across several bonds around a ring. Theterm “aromatic” as used herein refers to a group containing an aromaticring or ring system typically, although not necessarily, containing 2 to50 carbon atoms, preferably 2 to 25 carbon atoms, more preferably 2 to16 carbon atoms. Typical neutral unsubstituted aromatic compoundsinclude benzene, naphthalene, anthracene, phenanthrene, pyridine,pyrazine, imidazole, pyrazole, oxazole, thiophene, pyrrole, triazole,indole, and benzimidazole. Typical charged unsubstituted aromaticcompounds include cyclopropenyl cation and cyclopentadienyl anion. Theterm “aryl” as used herein refers to groups containing an aromatic ringor ring system typically, although not necessarily, containing 2 to 50carbon atoms, preferably 2 to 25 carbon atoms, more preferably 2 to 16carbon atoms. Aryl groups herein include groups containing a singlearomatic ring or multiple aromatic rings that are fused together, linkedcovalently, or linked to a common group such as a methylene or ethylenemoiety. More specific aryl groups contain one aromatic ring or two orthree fused or linked aromatic rings, e.g., phenyl, naphthyl, biphenyl,terphenyl, anthracenyl, phenanthrenyl, pyridinyl, pyrazinyl, imidazolyl,pyrazolyl, oxazolyl, thienyl, pyrrolyl, triazolyl, indolyl, andbenzimidazolyl. The aryl groups may be unsubstituted or may besubstituted with halogen, preferably fluorine, chlorine, or bromine,more preferably fluorine or bromine, even more preferably fluorine;hydrocarbyl, such as alkyl, alkenyl, or alkynyl, heterohydrocarbyl; orheteroatom groups. In particular embodiments, aryl substituents(substituents on the aryl group) include 1 to 40 atoms other thanhydrogen, preferably 1 to 20 atoms other than hydrogen, and morepreferably 1 to 10 atoms other than hydrogen. Substituted aryl groupsinclude tolyl (methylphenyl), xylyl (dimethylphenyl), mesityl(trimethylphenyl), ethylphenyl, styryl, allylphenyl, propynylphenyl,chlorophenyl, fluorophenyl, difluorophenyl, trifluorophenyl,tetrafluorophenyl, pentafluorophenyl, pentafluorobiphenyl,methoxyphenyl, ethoxyphenyl, dimethoxyphenyl, trifluoromethylphenyl,bis(trifluoromethyl)phenyl, dimethylaminophenyl,dimethylaminoethylphenyl, phenoxyphenyl, methylcarboxyphenyl,ethylcarboxyphenyl, methoxynaphthyl, nitrophenyl, dinitrophenyl,cyanophenyl, dicyanophenyl, chloropyridinyl, methylimidazolyl,phenylpyrrolyl, and ethylthienyl.

The term “arylalkyl” as used herein refers to substituted alkyl groups,the alkyl groups defined as above, wherein the substituent is one ormore aryl groups and typically, although not necessarily, containing 2to 50 carbon atoms, more preferably 2 to 25 carbon atoms, mostpreferably 2 to 16 carbon atoms, e.g., benzyl, tolylmethyl, xylylethyl,naphthylmethyl, anthracenylmethyl, 1-phenylethyl, 2-phenylethyl,diphenylmethyl, 2,2-diphenylethyl, phenylbutyl, fluorobenzyl,difluorobenzyl, trifluorobenzyl, chlorobenzyl, dichlorobenzyl,trichlorobenzyl, dimethylaminobenzyl, pyridylmethyl, diphenylpropyl,methoxybenzyl, and dinitrophenylethyl.

By “divalent”, e.g., “divalent hydrocarbon derivative”, “divalentheterohydrocarbon derivative”, “divalent moiety”, “divalent linkinggroup”, “divalent group”, “divalent hydrocarbyl”, “divalentheterohydrocarbyl”, “divalent heteroatom group”, “divalent alkyl”,“divalent aryl”, “divalent arylalkyl”, is meant that the hydrocarbonderivative, heterohydrocarbon derivative, moiety, linking group, group,hydrocarbyl, heterohydrocarbyl, heteroatom group, alkyl, aryl,arylalkyl, or other moiety is bonded at two points (a ‘diyl’ group) toatoms, molecules or moieties with the two bonding points being covalentsingle bonds, or, alternatively, is bonded at one point (an ‘ylidene’group) to an atom, molecule or moiety with the bonding point being acovalent double bond.

Phosphacycle-Containing Ligating Compound

In an embodiment of the invention, the invention comprises aphosphacycle-containing ligating compound (“ligating compound”). Theligating compound may be useful in the coordination, chelation, andsequestration of metals, and as precursors in forming ligatingcompound-metal complexes which are useful in catalysis, especially inhydroformylation, isomerization, hydrogenation, polymerizationprocesses, especially the oligomerization of olefins such as ethylene.The ligating compound may be represented by:

wherein P is phosphorus; X₁ is selected from, nitrogen, phosphorus,oxygen, or sulfur, preferably nitrogen or phosphorus, more preferablyphosphorus; in is 0 or 1; each L is independently selected from boron,carbon, silicon, germanium, nitrogen, phosphorus, oxygen, or sulfur,preferably carbon, nitrogen, phosphorus, oxygen, or sulfur, morepreferably carbon or nitrogen; R₁ and R₂ are each independently selectedfrom substituted or unsubstituted hydrocarbon derivatives, substitutedor unsubstituted heterohydrocarbon derivatives, or a substituted orunsubstituted heteroatom group; R₁, P, and R₂ together form aphosphacycle; when R₃, R₄, and X₁ are linked together, they form aphosphacycle when X₁ is phosphorus and they form an azacycle when X₁ isnitrogen; two or more R₁, R₂, R₃, R₄ or R₅ groups are optionally linkedtogether to form cyclic structures containing from 4 to 10 ring atoms,preferably from 4 to 7 ring atoms, wherein the optional character of thelinkages is depicted by a dashed connection; two or more R₅ groupsindependently are linked together with at least one L atom to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; two R₅ groups attached to the same L atom may beoptionally linked together to form a cyclic structure that contains from3 to 10 ring atoms, preferably from 3 to 7 ring atoms; optionally fromtwo to ten, preferably from two to six, independently selected ligatingcompounds may be linked together via their respective independentlyselected R₁, R₂, R₃, R₄ or R₅ groups to form a poly(ligating compound)species, R₃; R₄, and R₅ are each independently selected from hydrogen,halogen, substituted or unsubstituted hydrocarbon derivatives,substituted or unsubstituted heterohydrocarbon derivatives, or asubstituted or unsubstituted heteroatom group; p is an integer numberfrom 1 to 6, preferably from 1 to 4, more preferably from 1 to 3, mostpreferably from 1 to 2; q is 0, 1, or 2; provided that the [L]_(p)subunit of the divalent linking group

does not comprise an amidine (N—C═N) group; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; still furtherpreferably provided that one or two phosphacycles comprising P or X₁,preferably comprising P, R₁, and R₁, or comprising X₁, R₃, and R₄,contain no P—N, P—O, or P—S bonds within the ring part of thephosphacycle. Preferably at least one, preferably two, phosphacycles donot contain more than one carbon-carbon unsaturated bond in eachphosphacycle, preferably not more than one unsaturated bond in eachphosphacycle. Phosphacycles or azacycles are ring or cyclic compoundscomprising at least one phosphorus or nitrogen atom, respectively, inthe ring or cycle.

Each R₁ and R₂ independently contains from 1 to 50 non-hydrogen atoms;each R₃, R₄, and R₅ independently contains from 0 to 50 non-hydrogenatoms; preferably each R₅ independently contains from 0 to 40non-hydrogen atoms, more preferably from 0 to 20 non-hydrogen atoms, andmost preferably from 0 to 12 non-hydrogen atoms; optionally, at leastone R₅ group is a divalent group bonded to L via a double bond.

Preferably the ligating compound is represented by

wherein q is 0, 1, or 2; p is 1, 2, 3, or 4; t is 0, 1, 2, 3, or 4; v is0, 1, 2, 3, or 4; m is 0 or 1; L, R₃, R₄, R₅, and X₁ are as definedabove; further provided that in at least one phosphacyclc of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₁ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compounds may be linked together via their respectiveindependently selected R₃, R₄ or R₅ groups to form a poly(ligatingcompound) species.

Preferably X₁ is nitrogen or phosphorus; p=1, 2, 3, or 4; q=0, 1 or 2; vand t are each independently 1, 2, 3, or 4; R₅ are each independentlyhydrogen; halogen; C₁₋₄₀ substituted or unsubstituted hydrocarbonderivative, preferably C₁₋₂₀ substituted or unsubstituted hydrocarbonderivative, more preferably C₁₋₁₂ substituted or unsubstitutedhydrocarbon derivative; C₁₋₄₀ substituted or unsubstitutedheterohydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms; R₃ and R₁ are each independently C₁₋₄₀ substituted orunsubstituted hydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted hydrocarbon derivative, more preferably C₁₋₁₂ substitutedor unsubstituted hydrocarbon derivative; C₁₋₄₀ substituted orunsubstituted heterohydrocarbon derivative, preferably C₁₋₂₀ substitutedor unsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms, more preferably one atom; when X₁ and its two attached R₃ and R₄groups form a cycle represented as:

the cycle is an azacycle when X₁ is nitrogen and a phosphacycle when X₁is phosphorus; P and its two attached R₁ and R₂ groups form aphosphacycle represented as:

Preferably the L atoms of the phosphacycle or azacycle are eachindependently carbon, nitrogen, or oxygen; [L(R₅)_(q)]_(p) is as definedabove. Preferably all L atoms of either phosphacycle which are directlyattached to the phosphorus of the phosphacycle are carbon;[L(R₅)_(q)]_(p) is as defined above.

As is known to one skilled in the art, a carbon atom is chiral when thecarbon atom is attached to four different types of atoms or groups ofatoms, thus each ring carbon atom in the 4- to 7-membered phosphacycleor azacycle rings, respectively, is chiral when the ring carbon atom isattached to four different types of atoms or groups of atoms, that is,when its two attached R₅ groups and its two attached ring substituentsdiffer from each other. The configuration around a chiral atom isconsidered to be S or R and depends on the arrangement of the atoms orgroups of atoms attached to the atom. In the cases when t and v are eachindependently 1, 2, 3, or 4, L is carbon or nitrogen; and at least one Latom of the phosphacycle or azacycle is carbon, that at least one Lwhich is carbon in each of the 4-, 5-, 6-, and 7-membered rings ispotentially chiral. If a ring contains chiral carbon atoms, the ringitself may or may not be chiral; this, as is known to one skilled in theart, depends on the symmetry. The configurational possibilities of thephosphacycle or azacycle rings of the invention are: a) no carbon atomof the ring is chiral and the ring is not considered chiral; b) at leastone of the carbon atoms of the ring is chiral, that is, either with anReconfiguration or an S-configuration and the corresponding ring isconsidered have the R- or S-configuration for each chiral carbon. In thecase that exactly one carbon atom in the ring is chiral, the carbon mayhave either the R configuration or the S configuration and theconfiguration of the ring is considered to be R or S, respectively. Inthe case that exactly two carbon atoms in the ring are chiral, thecarbon atoms have the R,R; R,S; S,R; or S,S configurations, and theconfigurational possibilities of the ring are considered to be R,R; R,S;S,R; or S,S. In the case that exactly three carbon atoms in the ring arechiral, the carbon atoms may have the R,R,R; R,R,S; R,S,R; S,R,R; R,S,S;S,R,S; S,S,R; or S,S,S configurations, and the configurationalpossibilities of the ring are considered to be R,R,R; R,R,S; R,S,R;S,R,R; R,S,S; S,R,S; S,S,R; and S,S,S. One skilled in the art willrecognize how to determine the R and S configurations of the atoms andthe configurational possibilities of the rings with four, five, six, ormore chiral carbon atoms.

In addition to the R and S designators indicating the configuration ofthe particular carbon atom, numerical designators may also be used toindicate the position in the ring of the particular carbon atom. As amatter of convention, the phosphorus atom or the nitrogen atom of therespective phosphacycle or azacycle attached to Y or to the[L(R₅)_(q)]_(p) group representing Y is considered to be at the1-position. For example, in the following six-membered phosphacyclewhich has the name of (2R,5S)-2-methyl-5-phenylphosphorinanyl:

P is at the 1-position, the carbon atom with the attached methyl groupat the 2-position has an R-configuration as indicated by 2R, while thecarbon atom with the attached phenyl group at the 5-position has anS-configuration as indicated by 5S.

The phosphorus atom of the phosphacycle is potentially chiral whereinthe lone pair of electrons is relatively stable to inversion and is,therefore, counted as one of the four substituents on the phosphorusatom. The R-, S-, and achiral configurations of the phosphorus atoms ofthe ligating compounds, the ligating compound-chromium complexes, andthe catalyst systems are embodiments of the invention although in thisapplication the phosphorus atoms will not be given specific R- andS-configurational designations.

The above R and S configurational designators, as well as the numericaldesignators described above, clarify the configuration and position ofselected atoms in the phosphacycles or azacycles of the invention. Allpossible R- and S-enantiomers are considered to be objects of theinvention, including the cases when the configuration is not known.Unless otherwise so designated with a specific R- or S-configurationaldesignation, e.g., in a name or in a caption, any drawing which appearsto impute a particular stereo-orientation to an atom will be deemed torepresent all possible stereo-orientations and that any and all R- orS-configurational enantiomers or stereoisomers of the ligatingcompounds, the ligating compound-chromium complexes, and the catalystsystems are considered to be embodiments of the invention. For example,in the depiction of the following fragment of a ligating compound:

the carbon atom with the attached methyl group at the 2-position isspecified to have an R-configuration and the carbon atom with theattached phenyl group at the 5-position is specified to have anS-configuration and thus the fragment has the (2R,5S) configuration,while the depiction of the same fragment:

which does not specifically designate the configuration at the 2- and5-positions with R or S descriptors, is considered to mean that theconfigurations are unspecified and all possible configurations of thefragment, that is, (2R,5R), (2R,5S), (2S,5R), and (2S,5S) are meant.

Preferred ligating compounds are represented by:

wherein [L(R₅)_(q)] of the phosphacycle or azacycle independentlyselected is C(R₅), O, N, N(R₅), or C(R₅)₂; [L(R₅)_(q)]_(p) is as definedabove; q is 0, 1, or 2; p is 1, 2, 3, or 4; t is 1, 2, 3, or 4; v is 1,2, 3, or 4; m is 0 or 1, X₁ is nitrogen, phosphorus, or oxygen,preferably nitrogen or phosphorus, more preferably phosphorus; R₅ areeach independently hydrogen; halogen; C₁₋₄₀ substituted or unsubstitutedhydrocarbon derivative, preferably C₁₋₂₀ substituted or unsubstitutedhydrocarbon derivative, more preferably C₁₋₁₂ substituted orunsubstituted hydrocarbon derivative; C₁₋₄₀ substituted or unsubstitutedheterohydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms; R₃ and R₄ are each independently C₁₋₄₀ substituted orunsubstituted hydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted hydrocarbon derivative, more preferably C₁₋₁₂ substitutedor unsubstituted hydrocarbon derivative; C₁₋₄₀ substituted orunsubstituted heterohydrocarbon derivative, preferably C₁₋₂₀ substitutedor unsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms, more preferably one atom; further provided that in at least onephosphacycle of the phosphacycle-containing ligating compound, bothatoms directly bonded to P or X₁ are sp³ hybridized; two or more R₃, R₄or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms, preferably from 4 to 7 ring atoms;two or more R₅ groups independently are linked together with at leastone L atom to form a cyclic structure that contains from 3 to 10 ringatoms, preferably from 3 to 7 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; optionally from two to ten, preferably from two to six,independently selected ligating compounds may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound) species. More preferably p=1 or 2. Morepreferably all [L(R₅)_(q)] groups of either phosphacycle which aredirectly attached to the phosphorus of the phosphacycle areindependently C(R₅) or C(R₅)₂.

The number of chiral ring atoms, not including the P or X₁ attached to[L(R₅)_(q)]_(p) in each of the 4-, 5-, 6-, and 7-membered phosphacycleor azacycle rings in the ligating compound can range from zero (none) upto one less than the number of ring atoms in each ring. In someembodiments, no carbon atoms in either of the one or two 4-, 5-, 6-, and7-membered phosphacycle or azacycle rings are chiral. In someembodiments, only one carbon atom in the one or two 4-, 5-, 6-, and7-membered phosphacycle or azacycle rings is chiral. In someembodiments, only one carbon atom in each of the one or two 4-, 5-, 6-,and 7-membered phosphacycle or azacycle rings is chiral. In someembodiments, at least one of the carbon atoms in at least one of the oneor two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings ischiral. In some embodiments, at least one of the carbon atoms in each ofthe one or two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle ringsis chiral. In some embodiments, at least two of the carbon atoms in anyone of the 4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings arechiral. In some embodiments, at least two of the carbon atoms in atleast one of the one or two 4-, 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, at least two of thecarbon atoms in each of the one or two 4-, 5-, 6-, and 7-memberedphosphacycle or azacycle rings are chiral. In some embodiments, exactlytwo of the carbon atoms in at least one of the one or two 4-, 5-, 6-,and 7-membered phosphacycle or azacycle rings are chiral. In someembodiments, exactly two of the carbon atoms in each of the one or two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least three of the carbon atoms in any one of the4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least three of the carbon atoms in at least one ofthe one or two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle ringsare chiral. In some embodiments, at least three of the carbon atoms ineach of the one or two 4-, 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, exactly three of thecarbon atoms in at least one of the one or two 4-, 5-, 6-, and7-membered phosphacycle or azacycle rings are chiral. In someembodiments, exactly three of the carbon atoms in each of die one or two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least four of the carbon atoms in any one of the5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least four of the carbon atoms in at least one ofthe one or two 5-, 6-, and 7-membered phosphacycle or azacycle rings arechiral. In some embodiments, at least four of the carbon atoms in eachof the one or two 5-, 6-, and 7-membered phosphacycle or azacycle ringsare chiral. In some embodiments, exactly four of the carbon atoms in atleast one of the one or two 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, exactly four of thecarbon atoms in each of the one or two 5-, 6-, and 7-memberedphosphacycle or azacycle rings are chiral. The ligating compound may ormay not be optically active.

Preferably, when the ligating compound contains only one 4-, 5-, 6-, and7-membered phosphacycle ring and no azacycle ring attached to[L(R₅)_(q)]_(p), one, preferably two, L atoms in the phosphacycle ringattached to the P atom in the phosphacycle ring which is attached to[L(R₅)_(q)]_(p) are car bon, and one, more preferably two, of these Latoms are chiral. Preferably, when the ligating compound contains two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings attached to[L(R₅)_(q)]_(p), one to four L atoms in the phosphacycle or azacyclerings attached to the P or N atoms in the phosphacycle or azacycle ringswhich are attached to [L(R₅)_(q)]_(p) are carbon atoms, and one,preferably two, more preferably three, most preferably four of these Latoms are chiral.

In some embodiments, none of the 4-, 5-, 6-, and 7-membered phosphacycleor azacycle rings of the invention is chiral, preferably one or more4-membered rings have chiral carbon atoms at the 2- and 4-positions,preferably both chiral carbon atoms have the R configuration or bothhave the S configuration; one or more 5-membered rings have chiralcarbon atoms at the 2- and 5-positions, preferably both chiral carbonatoms have the R configuration or both have the S configuration; one ormore 6-membered rings have chiral carbon atoms at the 2- and6-positions, preferably both chiral carbon atoms have the Rconfiguration or both have the S configuration; and one or more7-membered rings have chiral carbon atoms at the 2- and 7-positions,preferably both chiral carbon atoms have the R configuration or bothhave the S configuration. Preferably one, more preferably two, 4-, 5-,6-, and 7-membered phosphacycle or azacycle rings have exactly twochiral carbon atoms in each ring.

The ligating compound may comprise a single isomer or mixture of variousisomers, including stereoisomers, whether configurational,conformational, geometric, or optical. Mixtures of ligating compoundscomprising chiral ligating compounds which are racemic, enantioenriched,or enantiomerically pure are preferred.

The ligating compound having only one 4-, 5-, 6-, and 7-memberedphosphacycle ring and no azacycle ring, and wherein the phosphacyclering has two chiral carbons, may have the following configurationalisomers: R,R; R,S; S,R; and S,S. In an embodiment of the invention, theligating compound is a mixture of ligating compounds substantiallycomprising the R,S and S,R isomers of a single ligating compound in anyproportion, more preferably the ligating compound is a mixture ofligating compounds substantially comprising the R,R and S,S isomers of asingle ligating compound in any proportion.

When the ligating compound has one 4-, 5-, 6-, or 7-memberedphosphacycle ring and one additional 4-, 5-, 6-, or 7-memberedphosphacycle or azacycle ring wherein each ring has two chiral carbons,the ligating compound may have the following configurational isomers:R,R,R,R; R,R,R,S; R,R,S,R; R,S,R,R; S,R,R,R; R,R,S,S; R,S,R,S; S,R,R,S;R,S,S,R; S,R,S,R; S,S,R,R; R,S,S,S; S,R,S,S; S,S,R,S; S,S,S,R; andS,S,S,S; the configurational isomers of the ligating compound are acombination of the configurational isomers of the two phosphacycle andazacycle rings, each having the configurational choices of R,R; R,S;S,R; and S,S; each of the foregoing is an embodiment of die invention.Preferably both phosphacycle or azacycle rings of the ligating compoundhave the same configuration, for example, both are R,R or R,S or S,R orS,S, whereby preferred isomer configurations of the ligating compoundare R,R,R,R; R,S,R,S; S,R,S,R; and S,S,S,S.

In a preferred embodiment of the invention, the ligating compound is amixture substantially comprising the R,S,R,S and S,R,S,R isomers of asingle ligating compound in any proportion, more preferably the ligatingcompound is a mixture substantially comprising the R,R,R,R and S,S,S,Sisomers of a single ligating compound in any proportion.

Preferably [L(R₅)_(q)] of the phosphacycle or azacycle independentlyselected is C(R₅), N, N(R₅), or C(R₅)₂; X₁ is phosphorus or nitrogen; tand v are each independently 1, 2, 3, or 4. Preferably one to six[L(R₅)_(q)] groups of each 4-, 5-, 6-, and 7-membered phosphacycle orazacycle are C(R₅) or C(R₅)₂, more preferably C(R₅)₂. Preferably atleast one, more preferably two, even more preferably three, still morepreferably four, [L(R₅)_(q)] groups of each phosphacycle or azacycle areC(R₅)₂. Preferably at least one, more preferably two, [L(R₅)_(q)] groupsof each phosphacycle or azacycle are C(R₅). Preferably one, morepreferably two, of the C(R₅) or C(R₅)₂ groups of at least onephosphacycle or azacycle are attached to a P or N atom in thephosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p).Preferably both R₅ groups of the one, more preferably two, C(R₅)₂ groupsattached to a P or N atom in at least one phosphacycle or azacycle whichis attached to [L(R₅)_(q)]_(p) are identical; more preferably they arenot identical. Preferably exactly one R₅ group of at least one,preferably two, C(R₅) or C(R₅)₂ groups attached to a P or N atom in atleast one phosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p)is hydrogen, more preferably exactly one R₅ group of at least one,preferably two, C(R₅) or C(R₅)₂ groups attached to a P or N atom in atleast one phosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p)is not hydrogen. Preferably both C(R₅) or C(R₅)₂ groups attached to a Por N atom in at least one phosphacycle or azacycle which is attached to[L(R₅)_(q)]_(p) are identical to each other. More preferably twoC(R₅)_(q) groups are attached to a P or N atom in each phosphacycle orazacycle which is attached to [L(R₅)_(q)]_(p). More preferably all[L(R₅)_(q)] groups of the phosphacycles or azacycle which are directlyattached to the P or N atom in each phosphacycle or azacycle areindependently C(R₅)_(q) as represented by:

and their enantiomers wherein C(R₅)_(q) is C(R₅), C(R₅)₂, or C(R₅)H,preferably C(R₅)H; X₁ is phosphorus or nitrogen; preferably the R₅groups of the C(R₅)H groups attached to the P or N atom in eachphosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p) are nothydrogen, and wherein, as mentioned above, both the R-configuration andthe S-configuration are meant for C(R₅)H; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; two or moreR₃, R₁ or R₅ groups are optionally linked together to form cyclicstructures containing from 4 to 10 ring atoms, preferably from 4 to 7ring atoms; two or more R₅ groups independently are linked together withat least one L atom to form a cyclic structure that contains from 3 to10 ring atoms, preferably from 3 to 7 ring atoms; two R₅ groups attachedto the same L atom may be optionally linked together to form a cyclicstructure that contains from 3 to 10 ring atoms, preferably from 3 to 7ring atoms; optionally from two to ten, preferably from two to six,independently selected ligating compounds may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound) species. Preferably both C(R₅)H groups attachedto the P or N atom in the phosphacycle or azacycle which is attached to[L(R₅)_(q)]_(p) are the same. Preferably both C(R₅)H groups attached tothe P atom in the phosphacycle which is attached to [L(R₅)_(q)]_(p) havethe same R or S configuration. Preferably when X₁ is a P atom and X₁,R₃, and R₄ form a phosphacycle, the phosphacycle is identical to thephosphacycle formed by P, R₁ and R₂. Preferably the L atoms ofphosphacycles or azacycles are independently carbon or nitrogen.Preferably at least two L atoms in each phosphacycle or azacycle arecarbon. Preferably t and v are each independently 1, 2, or 3, preferably1 or 2. Preferably at least one of t and v is 2, more preferably t is 2.In a preferred embodiment, t is 2; and at least one, preferably two, ofL in the phosphacycle is carbon. In a preferred embodiment, t is 2; andat least one, preferably two, of L in the phosphacycle is nitrogen. In apreferred embodiment, v is 2; and at least one, preferably two, of L inthe ring comprising X₁ are carbon. In a preferred embodiment, v is 2;and at least one, preferably two, of L in the ring comprising X₁ arenitrogen. More preferably X₁ is phosphorus. More preferably t and v areeach 2. More preferably t and v are each 2 and X₁ is phosphorus. In apreferred embodiment, the X₁, R₃, and R₄ groups of X₁R₃(R₄)_(m) do notform a cycle, m is 0 or 1, preferably m is 1; preferably X₁ is nitrogen,more preferably X₁ is phosphorus.

In preferred ligating compounds X₁ is phosphorus and 5-membered ligatingcompounds are represented by:

wherein q is 1 or 2; preferably L(R₅)_(q) of the phosphacycles is C(R₅),N(R₅), or C(R₅)₂, preferably [L(R₅)_(q)]_(p) is C(R₅), N(R₃), C(R₅)₂,C(R₅)C(R₅) or C(R₅)₂C(R₅)₂, more preferably N(R₅) or C(R₅)C(R₅); theC(R₅)_(q) attached to P is C(R₅), C(R₅)₂, or C(R₅)H, preferably C(R₅)H;further provided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compounds may be linked together via their respectiveindependently selected R₃, R₄ or R₅ groups to form a poly(ligatingcompound) species. Preferably at least one, more preferably two,phosphacycles contain at least one, preferably two, [L(R₅)_(q)] groupseach which are C(R₅) or C(R₅)₂. At most one bond in at least onephosphacycle is an unsaturated bond, preferably all bonds in at leastone phosphacycle are saturated bonds. Preferably at least one,preferably two, 5-membered phosphacycles are saturated, meaning theycontain no unsaturated bonds. Preferably one 5-membered phosphacycle issaturated, and one phosphacycle, preferably one 5-membered phosphacycle,has two unsaturated bonds, preferably exactly one unsaturated bond.Preferably one 5-membered phosphacycle has exactly one unsaturated bond,and one phosphacycle, preferably one 5-membered phosphacycle, has twounsaturated bonds, preferably exactly one unsaturated bond, morepreferably no unsaturated bonds. Preferably the unsaturated bonds arecarbon-carbon unsaturated bonds. Preferably the unsaturated bonds arecarbon-nitrogen unsaturated bonds.

Saturated 5-membered phosphacycles are known as phospholanes when allfour ring atoms besides phosphorus are carbon; azaphospholanes whenthree ring atoms besides phosphorus are carbon and one ring atom isnitrogen; diazaphospholanes when two ring atoms besides phosphorus arecarbon and two ring atoms besides phosphorus are nitrogen. Unsaturated5-membered phosphacycles with exactly one unsaturated bond, are known asdihydrophospholes when all four ring atoms besides phosphorus arecarbon; dihydroazaphospholes when three ring atoms besides phosphorusare carbon and one L atom is nitrogen; dihydrodiazaphospholes when tworing atoms besides phosphorus are carbon and two ring atoms besidesphosphorus are nitrogen. Unsaturated 5-membered phosphacycles with twounsaturated bonds are known as phospholes. The convention used hereinfor naming the 5-membered phosphacycles places the phosphorus at the1-position, the two ring-atoms attached to phosphorus are at the 2- and5-positions, while the remaining two ring-atoms not attached tophosphorus are at the 3- and 4-positions.

Preferred 5-membered phosphacycles of the ligating compound areindependently selected, as represented by:

and their enantiomers.

Referred 5-membered ring phosphacycle-containing ligating compounds maybe built up by independently selecting one preferred 5-memberedphosphacycle from above, connecting it to one valence of the[L(R₅)_(q)]_(p) divalent linking group, and connecting the remainingfree valence of the divalent linking group either to a secondindependently selected phosphacycle, preferably a preferred 5-memberedphosphacycle from above, or to X₁R₃R₄, wherein X₁ is phosphorus ornitrogen, preferably phosphorus.

Non-limiting examples of preferred non-5-membered ringphosphacycle-containing ligating compounds are represented by:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₅ groups are optionally linkedtogether to form cyclic structures containing from 4 to 10 ling atoms,preferably from 4 to 7 ring atoms; two or more R₅ groups independentlyare linked together with at least one L atom to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; two R₅ groups attached to the same L atom may be optionallylinked together to form a cyclic structure that contains from 3 to 10ring atoms, preferably from 3 to 7 ring atoms; optionally from two toten, preferably from two to six, independently selected ligatingcompounds may be linked together via their respective independentlyselected R₅ groups to form a poly(ligating compound) species. Preferablythe [L(R₅)_(q)]_(p) divalent linking group is NR₅, C(R₅), C(R₅)C(R₅),C(R₅)₂ or C(R₅)₂C(R₅)₂, preferably N(R₅).

Non-limiting examples of the preferred 5-membered ringphosphacycle-containing ligating compounds are represented by:

and their enantiomers wherein two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; further providedthat in at least one phosphacycle of the phosphacyclc-containingligating compound, both atoms directly bonded to P or X₁ are sp³hybridized; two or more R₅ groups independently are linked together withat least one L atom to form a cyclic structure that contains from 3 to10 ring atoms, preferably from 3 to 7 ring atoms; two R₅ groups attachedto the same L atom may be optionally linked together to form a cyclicstructure that contains from 3 to 10 ring atoms, preferably from 3 to 7ring atoms; optionally from two to ten, preferably from two to six,independently selected ligating compounds may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound) species. Preferably the [L(R₃)_(q)]_(p) divalentlinking group is NR₅, C(R₅), C(R₅)C(R₅), C(R₅)₂ or C(R₅)₂C(R₅)₂,preferably N(R₅).

Preferably exactly one R₅ group in at least one, preferably two, C(R₅)or C(R₅)₂ groups attached to the P atom in at least one, preferably two,phosphacycles is hydrogen. Representative, but not limiting, examplesare:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compounds may be linked together via their respectiveindependently selected R₃, R₄ or R₅ groups to form a poly(ligatingcompound) species.

Preferably any R₅ groups attached to the nitrogen atoms in the5-membered phosphacycles are not hydrogen, preferably any R₅ groupsattached to the nitrogen atoms in the 5-membered phosphacycles arehydrocarbyl, preferably C₁₋₄ alkyl, C₆₋₁₀ aryl, or C₇₋₁₀ arylalkyl, morepreferably methyl, ethyl, phenyl, benzyl, or tolyl; preferably the R₅groups attached to the ring carbon atom of the C(R₅) or C(R₅), groups atthe 3- and 4-positions on the 5-membered phosphacycle are hydrogenatoms; preferably the R₅ groups attached to at least one of the ringcarbon atoms of the C(R₅) groups, wherein the ring carbon atoms of theC(R₅) groups are bonded to another ring atom by means of an unsaturatedbond, preferably carbon-carbon unsaturated bond, are hydrogen atoms orare part of an aromatic ring which is fused to the phosphacycle.

Representative, but not limiting, examples are:

and their enantiomers.

Preferably at least one, preferably two, of the R₅ groups attached tothe ring carbon atom of the C(R₅) or C(R₅)₂ groups at the 2- and5-positions on the 5-membered phosphacycle are independently alkyl,substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, preferably arylor substituted aryl; preferably exactly one R₅ group attached to thering carbon atom of the C(R₅) or C(R₅)₂ group at each 2-position and ateach 5-position on the 5-membered phosphacycle is alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroaryl, or substituted heteroaryl, preferably aryl, substitutedaryl, heteroaryl, or substituted heteroaryl, more preferably aryl orsubstituted aryl; preferably exactly one R₅ group attached to the ringcarbon atom of any C(R₅)₂ groups at each 2-position and at each5-position on the 5-membered phosphacycle is independently hydrogen,methyl, ethyl, propyl, butyl, or pentyl, preferably hydrogen or methyl,more preferably hydrogen; preferably R₃ and R₄ are independently alkyl,substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl, or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, more preferablyaryl or substituted aryl; preferably exactly one R₅ group attached tothe ring carbon atom of the C(R₅) or C(R₅)₂ group at each 2-position andat each 5-position on the 5-membered phosphacycle is independently arylor substituted aryl, exactly one R₅ group attached to the ring carbonatom of any C(R₅)₂ groups at each 2-position and at each 5-position onthe 5-membered phosphacycle is a hydrogen, and R₃ and R₄ areindependently alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl, or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, more preferablyaryl or substituted aryl. Preferably the aryl, substituted aryl,heteroaryl, or substituted heteroaryl groups at the 2-position and the5-position on the 5-membered phosphacycle are identical. Preferably R₃,R₄, and R₅ are each independently C₁₋₄₀ substituted or unsubstitutedalkyl, preferably C₁₋₂₀ substituted or unsubstituted alkyl, morepreferably C₁₋₁₂ substituted or unsubstituted alkyl; C₂₋₄₀ substitutedor unsubstituted aryl, preferably C₂₋₂₀ substituted or unsubstitutedaryl, more preferably C₂₋₁₂ substituted or unsubstituted aryl; C₁₋₄₀substituted or unsubstituted arylalkyl, preferably C₂₋₂₀ substituted orunsubstituted arylalkyl, more preferably C₂₋₁₂ substituted orunsubstituted arylalkyl; C₂₋₄₀ substituted or unsubstituted heteroaryl,preferably C₂₋₂₀ substituted or unsubstituted heteroaryl, morepreferably C₂₋₁₂ substituted or unsubstituted heteroaryl; preferably R₅independently is C₁₋₄ alkyl, C₆₋₁₀ aryl, or C₇₋₁₀ arylalkyl when R₅ isattached to a ring nitrogen atom of the 5-membered ring phosphacycle;further provided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compounds may be linked together via their respectiveindependently selected R₃, R₄ or R₅ groups to form a poly(ligatingcompound) species.

In a preferred embodiment, R₃, R₄, and R₅ attached to a ring nitrogenatom of the 5-membered ring phosphacycle are Ar, R₅ attached to a ringnitrogen atom of the 5-membered ring phosphacyclc is Ar′, wherein Arindependently is C₂₋₄₀ substituted or unsubstituted aryl, preferablyC₂₋₂₀ substituted or unsubstituted aryl, more preferably C₂₋₁₂substituted or unsubstituted aryl; C₂₋₄₀ substituted or unsubstitutedarylalkyl, preferably C₂₋₂₀ substituted or unsubstituted arylalkyl, morepreferably C₂₋₁₂ substituted or unsubstituted arylalkyl; C₂₋₄₀substituted or unsubstituted heteroaryl, preferably C₂₋₂₀ substituted orunsubstituted heteroaryl, more preferably C₂₋₁₂ substituted orunsubstituted heteroaryl, and Ar′ independently is C₁₋₄ alkyl, C₆₋₁₀aryl, or C₇₋₁₀ arylalkyl.

In preferred ligating compounds, L of the phosphacycles is carbon and5-membered ligating compounds are represented by:

wherein q is 1 or 2; preferably [L(R₅)_(q)]_(p) is C(R₅), N(R₅), C(R₅)₂,C(R₅)C(R₅) or C(R₅)₂C(R₅)₂, more preferably N(R₅) or C(R₅)C(R₅); theC(R₅)_(q) attached to P is C(R₅), C(R₅)₂, or C(R₅)H, preferably C(R₅)H.

In preferred ligating compounds, [L(R₅)_(q)]_(p) of the divalent linkinggroup is NR₅ and 5-membered ligating compounds are represented by:

wherein q is 1 or 2; the C(R₅)_(q) attached to P is C(R₅), C(R₅)₂, orC(R₅)H, preferably C(R₅)H.

In preferred ligating compounds, [L(R₅)_(q)] at the 3- and 4-positionsof the phosphacycle ring are CH₂; [L(R₅)_(q)] at the 2- and 5-positionsof the phosphacycle ring are CR₅H; [L(R₅)_(q)]_(p) of the divalentlinking group is NR₅, and 5-membered ligating compounds are representedby:

In preferred ligating compounds, [L(R₅)_(q)] at the 2- and 5-positionsof the phosphacycle ring are CR₅H; the carbon atoms at the 2- and5-positions are chiral; preferably both carbon atoms at the 2- and5-positions in each phosphacycle ring have the same R or Sconfiguration; [L(R₅)_(q)]_(p) of the divalent linking group is NR₅;preferably [L(R₅)_(q)] at the 3- and 4-positions of the phosphacyclering are CH₂, and 5-membered ligating compounds are represented by:

and their enantiomers.

Non-limiting examples of the ligating compounds are:

and their enantiomers.

In preferred ligating compounds, Ar at the 2- and 5-positions of thephosphacycle rings is phenyl optionally substituted with R₅;[L(R₅)_(q)]_(p) of the divalent linking group is NR₅; preferably[L(R₅)_(q)] at the 3- and 4-positions of the phosphacyclc ring are CH₂,and 5-membered ligating compounds are represented by:

and their enantiomers wherein n independently selected is an integerfrom zero to five, preferably from zero to three.

Preferably Ar independently is C₂₋₄₀ substituted or unsubstituted aryl,preferably C₂₋₂₀ substituted or unsubstituted aryl, more preferablyC₂₋₁₂ substituted or unsubstituted aryl; C₂₋₄₀ substituted orunsubstituted heteroaryl, preferably C₂₋₂₀ substituted or unsubstitutedheteroaryl, more preferably C₂₋₁₂ substituted or unsubstitutedheteroaryl. Preferably Ar is independently phenyl, substituted phenyl,furanyl, substituted furanyl, thienyl, substituted thienyl, pyrrolyl,substituted pyrrolyl, pyridinyl, and substituted pyridinyl, morepreferably phenyl, substituted phenyl, and furanyl. In at least onephosphacycle of the phosphacycle-containing ligating compound, bothatoms directly bonded to P or X₁ are sp³ hybridized; Two or more Ar, Ar′or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms, preferably from 4 to 7 ring atoms;two or more R₅ groups independently are linked together with at leastone L atom to form a cyclic structure that contains from 3 to 10 ringatoms, preferably from 3 to 7 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; optionally from two to ten, preferably from two to six,independently selected ligating compounds may be linked together viatheir respective independently selected Ar, Ar′ or R₅ groups to form apoly(ligating compound) species. When PR₃R₄ is non-cyclic (i.e., it doesnot form a phosphacycle), the atom of each R₃ or R₄ group directlyattached to the phosphorus-atom is considered to be at the 1-position ofthat particular group for the purpose of numbering the positions ofatoms or substituents in the R₃ or R₄ group. In a preferred embodimentof die ligating compounds wherein the PR₃R₄ group is non-cyclic, R₃ andR₄ independently are represented by alkyl, substituted alkyl, phenyl,substituted phenyl, furanyl, substituted furanyl, thienyl, substitutedthienyl, pyrrolyl, substituted pyrrolyl, pyridinyl, and substitutedpyridinyl; preferably the ligating compounds are represented by:

and their enantiomers wherein Ar independently is halogen; C₁₋₄₀substituted or unsubstituted alkyl, preferably C₁₋₂₀ substituted orunsubstituted alkyl, more preferably C₁₋₁₂ substituted or unsubstitutedalkyl, even more preferably C₁₋₆ substituted or unsubstituted alkyl,especially methyl, trifluoromethyl, methoxy, ethyl, ethoxy, propyl,isopropyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, hexyl; C₂₋₄₀substituted or unsubstituted aryl, preferably C₂₋₂₀ substituted orunsubstituted aryl, more preferably C₁₋₁₂ substituted or unsubstitutedaryl, especially phenyl, fluorophenyl, difluorophenyl, trifluorophenyl,tolyl, dimethylphenyl, t-butylphenyl, di-t-butylphenyl, methoxyphenyl,ethoxyphenyl, di-t-butylmethoxyphenyl, cyanophenyl, nitrophenyl; C₂₋₁₀substituted or unsubstituted heteroaryl, preferably C₂₋₂₀ substituted orunsubstituted heteroaryl, more preferably C₂₋₁₂ substituted orunsubstituted heteroaryl, especially substituted or unsubstitutedpyridyl, thienyl, furanyl, pyrrolyl; X″ independently is hydrogen;halogen, preferably fluorine, chlorine or bromine, more preferablyfluorine or chlorine, even more preferably fluorine; C₁₋₄₀ substitutedor unsubstituted alkyl, preferably C₁₋₂₀ substituted or unsubstitutedalkyl, more preferably C₁₋₁₂ substituted or unsubstituted alkyl, evenmore preferably C₁₋₆ substituted or unsubstituted alkyl, especiallymethyl, trifluoromethyl, methoxy, ethyl, ethoxy, propyl, isopropyl,n-butyl, i-butyl, s-butyl, t-butyl, pentyl, hexyl; C₂₋₄₀ substituted orunsubstituted aryl, preferably C₂₋₂₀ substituted or unsubstituted aryl,more preferably C₂₋₁₂ substituted or unsubstituted aryl, especiallyphenyl, fluorophenyl, difluorophenyl, trifluorophenyl, tolyl,dimethylphenyl; substituted or unsubstituted arylalkyl, preferably C₂₋₂₀substituted or unsubstituted arylalkyl, more preferably C₂₋₁₂substituted or unsubstituted arylalkyl, especially benzyl, phenethyl,and methylbenzyl; nitro or cyano; further provided that in at least onephosphacycle of the phosphacycle-containing ligating compound, bothatoms directly bonded to P or X₁ are sp³ hybridized; two or more Ar, X″or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms, preferably from 4 to 7 ring atoms;two or more R₅ groups independently are linked together with at leastone L atom to form a cyclic structure that contains from 3 to 10 ringatoms, preferably from 3 to 7 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; optionally from two to ten, preferably from two to six,independently selected ligating compounds may be linked together viatheir respective independently selected R₁, R₂, R₃, R₄ or R₅ groups toform a poly(ligating compound) species. X′″ is independently N, O or S,preferably O. Preferably X″ independently is hydrogen, fluorine,chlorine, methyl, methoxy, t-butyl, phenyl, nitro or cyano. PreferablyR₃ and R₄ independently are substituted or unsubstituted phenyl orunsubstituted furanyl. Preferably R₃ or R₄ independently is substitutedphenyl, and at least one X″ on at least one, preferably each,substituted phenyl is halogen, preferably fluorine or chlorine, C₁₋₄alkyl or substituted alkyl, preferably methyl, trifluoromethyl ort-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy, C₆₋₁₀ aryl,preferably phenyl or tolyl, cyano or nitro, more preferably fluorine,chlorine or methyl, even more preferably fluorine; preferably at leastone, more preferably each, substituted phenyl is substituted at the2-position with cyano, nitro, fluorine, chlorine, bromine or iodine,preferably fluorine or chlorine, more preferably fluorine and issubstituted at one or more of the 3-, 4-, 5-, 6-positions with cyano,nitro, fluorine, chlorine, bromine or iodine, preferably fluorine orchlorine, more preferably fluorine; preferably at least one, morepreferably each, substituted phenyl is independently substituted at the2-position and the 4-position with cyano, nitro, fluorine, chlorine,bromine or iodine, preferably fluorine or chlorine, more preferablyfluorine; preferably at least one, more preferably each, substitutedphenyl is substituted at the 2-position with cyano, nitro, fluorine,chlorine, bromine or iodine, preferably fluorine or chlorine, morepreferably fluorine; preferably at least one, more preferably each,substituted phenyl is substituted at the 6-position with hydrogen,fluorine or chlorine, preferably hydrogen or fluorine, more preferablyhydrogen; preferably at least one, more preferably each, substitutedphenyl is substituted at the 2-position with fluorine, at the 4-positionwith hydrogen or fluorine, and at the 6-position with hydrogen.Preferably R₃ and R₄ independently are substituted or unsubstitutedpyridinyl. Preferably R₃ or R₄ independently is substituted pyridinyl,and at least one X″ on at least one, preferably each, substitutedpyridinyl is halogen, preferably fluorine or chlorine, C₆₋₁₀ alkyl,preferably methyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy,C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, more preferablyfluorine, chlorine or methyl, even more preferably fluorine; preferablyat least one, more preferably each, substituted pyridinyl is substitutedat the 2-position with cyano, nitro, fluorine, chlorine, bromine oriodine, preferably fluorine or chlorine, more preferably fluorine.Preferably R₃ and R₄ independently are substituted or unsubstitutedpyridinyl. Preferably R₃ or R₁ independently is substituted pyridinyl,and at least one X″ on at least one, preferably each, substitutedpyridinyl is halogen, preferably fluorine or chlorine, C₁₋₄ alkyl,preferably methyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy,C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, more preferablyfluorine, chlorine or methyl, even more preferably fluorine. PreferablyR₃ and R₄ independently are substituted or unsubstituted pyrrolyl.Preferably R₃ or R₄ independently is substituted pyrrolyl, and at leastone X″ on at least one, preferably each, substituted pyrrolyl ishalogen, preferably fluorine or chlorine, C₁₋₄ alkyl, preferably methylor t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy, C₆₋₁₀ aryl,preferably phenyl or tolyl, cyano or nitro, more preferably fluorine,chlorine or methyl, even more preferably methyl. Preferably R₃ and R₄independently are substituted or unsubstituted furanyl. Preferably R₃ orR₄ independently is substituted furanyl, and at least one X″ on at leastone, preferably each, substituted furanyl is halogen, preferablyfluorine or chlorine, C₁₋₄ alkyl, preferably methyl or t-butyl, C₁₋₄alkoxy, preferably methoxy or ethoxy, aryl, preferably phenyl or tolyl,cyano or nitro, more preferably fluorine, chlorine or methyl, even morepreferably methyl. Preferably R₃ and R₄ independently are substituted orunsubstituted thienyl. Preferably R₃ or R₄ independently is substitutedthienyl, and at least one X″ on at least one, preferably each,substituted thienyl is halogen, preferably fluorine or chlorine, C₁₋₄alkyl, preferably methyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy orethoxy, C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, morepreferably fluorine, chlorine or methyl, even more preferably methyl.

Non-limiting examples of the ligating compounds are:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more Ar or R₅ groups are optionallylinked together to form cyclic structures containing from 4 to 10 ringatoms, preferably from 4 to 7 ring atoms; two or more R₃ groupsindependently are linked together with at least one L atom to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; two R₅ groups attached to the same L atom may beoptionally linked together to form a cyclic structure that contains from3 to 10 ring atoms, preferably from 3 to 7 ring atoms; optionally fromtwo to ten, preferably from two to six, independently selected ligatingcompounds may be linked together via their respective independentlyselected Ar or R₅ groups to form a poly(ligating compound) species.

In preferred ligating compounds, Ar at the 2- and 5-positions of thephosphacycle rings is phenyl optionally substituted with R₅;[L(R₅)_(q)]_(p) of the divalent linking group is NR₅, and 5-memberedligating compounds are represented by:

and their enantiomers, wherein n independently selected is an integerfrom zero to five, preferably from zero to three, more preferably zeroto one; R₅ is halogen, C₁₋₄₀ substituted or unsubstituted alkyl, C₁₋₄₀substituted or unsubstituted aryl; preferably fluorine, chlorine,bromine, C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₂₀ substituted orunsubstituted aryl; more preferably fluorine, chlorine, C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; R₃ is C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₄₀ substitutedor unsubstituted aryl; preferably C₁₋₂₀ substituted or unsubstitutedalkyl, C₁₋₂₀ substituted or unsubstituted aryl; more preferably C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; X″ is hydrogen, halogen, C₁₋₄ alkyl or substituted alkyl, C₆₋₁₀aryl or substituted aryl, cyano or nitro, preferably hydrogen, fluorine,chlorine, bromine, methyl, ethyl, propyl, butyl, phenyl, tolyl, xylyl,methoxy, ethoxy, propoxy, trifluoromethyl or t-butyl, cyano, morepreferably hydrogen, fluorine, chlorine, methyl, ethyl, propyl, butyl,phenyl, tolyl, methoxy, ethoxy, propoxy, trifluoromethyl, cyano, evenmore preferably hydrogen, fluorine, methyl, or methoxy.

In preferred ligating compounds, X″ at the 2-position of the phenyl ringattached to P is fluorine, X″ at the 6-position of the phenyl ringattached to P is hydrogen, and 5-membered ligating compounds arerepresented by:

and their enantiomers, wherein n independently selected is an integerfrom zero to five, preferably from zero to three, more preferably zeroto one; R₅ is halogen, C₁₋₁₀ substituted or unsubstituted alkyl, C₁₋₄₀substituted or unsubstituted aryl; preferably fluorine, chlorine,bromine, C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₂₀ substituted orunsubstituted aryl; more preferably fluorine, chlorine, C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; R₃ is C₁₋₄₀ substituted or unsubstituted alkyl, C₁₋₄₀ substitutedor unsubstituted aryl; preferably C₁₋₂₀ substituted or unsubstitutedalkyl, C₁₋₂₀ substituted or unsubstituted aryl; more preferably C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; X″ is hydrogen, halogen, C₁₋₄ alkyl or substituted alkyl, C₆₋₁₀aryl or substituted aryl, cyano or nitro, preferably hydrogen, fluorine,chlorine, bromine, methyl, ethyl, propyl, butyl, phenyl, tolyl, xylyl,methoxy, ethoxy, propoxy, trifluoromethyl or t-butyl, cyano, morepreferably hydrogen, fluorine, chlorine, methyl, ethyl, propyl, butyl,phenyl, tolyl, methoxy, ethoxy, propoxy, trifluoromethyl, cyano, evenmore preferably hydrogen, fluorine, methyl, or methoxy.

The group Y, which links P and X₁ together in the ligating compounds, isa divalent linking group [L(R₅)_(q)]_(p) wherein p is an integer numberfrom 1 to 6, preferably from 1 to 4, preferably 1, 2, or 3, morepreferably 1 or 2; q is 0, 1, or 2; consisting of the linking part[L]_(p) and the R₅ pendant groups wherein the R₅ pendant groupsindependently selected are attached to the L atoms of the [L]_(p)linking part. The linking part [L]_(p) consists of 1 to 6, preferably of1 to 4, preferably 1, 2, or 3, more preferably 1 or 2 L atoms; L isindependently selected from the group consisting of boron, carbon,silicon, germanium, nitrogen, phosphorus, oxygen, and sulfur. PreferablyL is independently selected from carbon, nitrogen, phosphorus, oxygen,and sulfur. Preferred linking parts [L]_(p), each L independentlyselected, are B, C, N, O, P, S, Si, C—C, C═C, C—N, C═N, C—Si, N—N,C—C—C, C—C═C, C—N—C, C—P—C, C—N═C, C—Si—C, N—C—N, C—N—N, C═N—N, C—N═N,C—O—C, and C—S—C, preferably provided that the linking part [L]_(p) isnot amidine, N—C═N. In an embodiment of the invention, each L(R₅)_(q)group is independently —N—, —N(R₅)—, —P(R₅)—, —P(O)(R₅)—, —P(S)(R₅)—,—C(O)—, —C(R₅)—, —C(R₅)₂—, —Si(R₅)₂—, —O—, —S—, S(O)—, and —SO₂—,preferably N, N(R₅), C(R₅), or C(R₅)₂.

In some embodiments, the linking part [L]_(p) consists of C and thedivalent linking group is [C(R₅)_(q)] wherein q is 1 or 2.Representative, but not limiting, [C(R₅)_(q)] linking groups include:

Specific, but not limiting, [C(R₅)_(q)] linking groups include:

In some embodiments, the linking part [L]_(p) is not C and the divalentlinking group is not [C(R₅)_(q)] wherein q is 1 or 2.

In some embodiments, the linking part [L]_(p) consists of C—C and thedivalent linking group is [C(R₅)_(q)]₂ wherein q independently is 1 or 2and at least one q is 2. Representative, but not limiting, [C(R₅)_(q)]₂linking groups include:

Specific, but not limiting, [C(R₅)_(q)]₂ linking groups include:

In some embodiments, the linking part [L]_(p) is not C—C and thedivalent linking group is not [C(R₅)_(q)]₂ wherein q independently is 1or 2 and at least one q is 2.

In some embodiments the linking part [L]_(p) consists of C—C and thedivalent linking group is [C(R₅)]₂ wherein both carbon atoms areconnected with a carbon-carbon unsaturated bond, or both carbon atomsare connected to their respectively R₅ groups with unsaturated bonds.Representative, but not limiting, [C(R₅)]₂ linking groups include:

Specific, but not limiting, [C(R₅)]₂ linking groups include:

In some embodiments the linking part [L]_(p) is not C—C and the divalentlinking group is not [C(R₅)]₂ wherein both carbon atoms are connectedwith a carbon-carbon unsaturated bond, or both carbon atoms areconnected to their respectively R₅ groups with unsaturated bonds.

In some embodiments, the linking part [L]_(p) consists of N or N—N andthe divalent linking group is [NR₅] or [NR₅]₂. Representative, but notlimiting, [NR₅] or [NR₅]₂ linking groups include:

Specific, but not limiting, [NR₅] or [NR₅]₂ linking groups include:

In some embodiments, the linking part [L]_(p) is neither N nor N—N andthe divalent linking group is neither [NR₅] nor [NR₅]₂. Preferably [NR₅]does not comprise

It will be appreciated that a diphosphinoimine compound of the formR₁R₂P—P(═NR₅)R₃(R₄) (‘P—P═N’) is a rearranged isomer of thediphosphinoamine compound R₁R₂P—NR₅—PR₃(R₄) (‘P—N—P’) claimed in thepresent invention, as shown by Dyson et al in Inorganica Chimica Acta359 (2006) 2635-2643 and may isomerize to the P—N—P form in the presenceof transition metals, such as chromium in the instant application.

Similarly, it may be possible that a ligating compound of the formR₁R₂P—Y—X₁R₃(R₄)_(m) or R₁R₂P-[L(R₅)_(q)]_(p)—X₁R₃(R₄)_(m) where Y or[L(R₅)_(q)]_(p) is —N(R₅)— and X₁R₃(R₄)_(m) is PR₃R₄, exists in itsisomeric ‘P—P═N’ form. Regardless of the structural formulation of theligating compound in its pure and isolated form, it and its use areembodiments of the present invention, especially if it exists in the‘P—N—P’ form when used in an oligomerization process, more especiallywhen it is bound to chromium in an oligomerization process.

In some embodiments, the linking part [L]_(p) consists of C—N and thedivalent linking group is [C(R₅)_(q)N(R₅)_(q)] wherein q independentlyis 1 or 2 for C(R₅)_(q) and 0 or 1 for N(R₅)_(q). Representative, butnot limiting, [C(R₅)_(q)N(R₅)] linking groups include:

Specific, but not limiting, [C(R₅)_(q)N(R₅)] linking groups include:

In some embodiments, the linking part [L]_(p) is not C—N and thedivalent linking group is not [C(R₅)_(q)N(R₅)_(q)] wherein qindependently is 1 or 2 for C(R₅)_(q) and 0 or 1 for N(R₅)_(q).Preferably [C(R₅)_(q)N(R₅)_(q)] does not comprise

In some embodiments, the L atoms of the linking part [L]_(p) areselected from the group consisting of B, O, S, Si, and C wherein atleast one L is not C; p is 1, 2, 3, or 4; and the divalent linking groupis [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] wherein X independently selected isBR₅, O, S, SO, SO₂, or Si(R₅)₂; k is 0 or 1; k′ is 0 or 1; r is 1, 2, or3. Preferably r+ k+ k′ 1, 2, or 3.

Representative, but not limiting, [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)]linking groups include:

Specific, but not limiting, [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] linkinggroups include:

In some embodiments, die L atoms of the linking part [L]_(p) are notselected from the group consisting of B, O, S, Si, and C wherein atleast one L is not C; p is 1, 2, 3, or 4; and the divalent linking groupis not [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] wherein X′ independentlyselected is BR₅, O, S, SO, SO₂, or Si(R₅)₂; k is 0 or 1; k′ is 0 or 1; ris 1, 2, or 3.

In preferred ligating compounds represented by:

the L atoms are connected to each other, independently for eachconnection, with single bonds or with unsaturated bonds with the provisothat in at least one phosphacycle of the ligating compound, both atomsdirectly bonded to P or X₁ are sp³ hybridized; preferably least onephosphacycle does not contain more than one carbon-carbon unsaturatedbond, preferably not more than one unsaturated bond, more preferably atleast one, preferably two, phosphacycles contain no unsaturated bonds;two or more R₃, R₄ or R₅ groups are optionally linked together to formcyclic structures containing from 4 to 10 ring atoms, preferably from 4to 7 ring atoms; two or more R₅ groups independently are linked togetherwith at least one L atom to form a cyclic structure that contains from 3to 10 ring atoms, preferably from 3 to 7 ring atoms; two R₅ groupsattached to the same L atom may be optionally linked together to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; optionally from two to ten, preferably from two tosix, independently selected ligating compounds may be linked togethervia their respective independently selected R₃, R₄ or R₅ groups to forma poly(ligating compound) species. In an embodiment of the invention notwo R₅, R₃, or R₄ groups are linked together to form a cyclic structure.In an embodiment of the invention at least two R₅ groups are linkedtogether to form a cyclic structure. Preferably at least one R″ group ona first L(R₅)_(q) group is linked together with at least one R₅ group onan adjacent second L(R₅)_(q) group together with the L atom from thefirst L(R₅)_(q) group and the L atom from the adjacent second L(R₅)_(q)group to form an

cyclic structure containing from 4 to 10 atoms, preferably 4 to 7 atoms,in the ring part of the

cyclic structure. Preferably the

ring is a substituted or unsubstituted, saturated or unsaturatedhydrocarbyl group, such as cyclopentanediyl, cyclohexanediyl,dioxolanediyl, tetrahydrofurandiyl, pyrrolidinediyl, piperidinediyl,piperazinediyl, pyrazolidinediyl. Preferably the

ring is a substituted or unsubstituted alkenyl or aromatic group, suchas cyclopentenediyl, cyclohexenediyl, cyclopentadienediyl, phenylene,naphthalenediyl, pyridinediyl, pyrrolediyl, imidazoldiyl,pyridazinediyl, pyridazinedionediyl, quinoxalinedtyl, thiazolediyl,thiophenediyl, furandiyl, or cyclopentadienyl-diyl, wherein preferablythe cyclopentadienyl group is part of an η⁵-bonded transition metalcomplex, wherein preferably the η⁵-bonded transition metal complexcomprises Fe, Ti, Zr, or Hf.

In an embodiment of the invention, two R₅ groups on the same L(R₅)_(q)group, wherein q=2, are linked together to form an

cyclic structure containing from 3 to 10 atoms, preferably 3 to 7 atoms,in the ring part of the

cyclic structure. Preferably the

ring is a substituted or unsubstituted, saturated or unsaturatedhydrocarbyl group, such as cyclobutanediyl, cyclopentanediyl,cyclohexanediyl, tetrahydrofurandiyl, or cyclopentenediyl.

In preferred ligating compounds of the invention, at least one R₅ groupon a L(R₅)_(q) group from at least one of the

groups or at least one R₅ group on a

group, wherein the R₃ or R₄ group may be represented as L(R₅)_(q)(R₅),is linked together with at least one R₅ group from the [L(R₅)_(q)]_(p)divalent bridging group between P and X₁ to form an

respectively, cyclic structure containing from 5 to 10 atoms, preferably5 to 7 atoms, in the ring part of the

cyclic structure.

R₃, R₄, and R₅ independently selected are hydrogen, fluoro, chloro,bromo, cyano; substituted or unsubstituted hydrocarbon derivatives,preferably substituted or unsubstituted alkyl groups having 1-20,preferably 1-12, more preferably 1-6, non-hydrogen atoms, preferablymethyl, trifluoromethyl, ethyl, propyl, isopropyl, n-butyl, i-butyl,s-butyl, t-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl; preferablysubstituted or unsubstituted unsaturated groups, including alkylidene,alkenyl, aryl, or arylalkyl groups, having 2-20, preferably 2-12, morepreferably 2-8, still more preferably 2-6, non-hydrogen atoms,preferably vinyl, methylidene, ethylidene, allyl, phenyl,2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,4-dimethylphenyl,2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2-isopropylphenyl,2,6-diisopropylphenyl, 2,6-diisopropyl-4-methylphenyl, 2-fluorophenyl,4-fluorophenyl, 2-trifluoromethylphenyl, naphthyl, anthracenyl,biphenyl, benzyl, naphthylmethyl phenethyl, biphenylmethyl; substitutedor unsubstituted heterohydrocarbon derivatives having 1-20, preferably1-12, more preferably 1-6, non-hydrogen atoms, preferably methoxy,ethoxy, propoxy, isopropoxy, butoxy, phenoxy, methylthio, ethylthio,acetyl, dimethylboryl, diphenylboryl, bis(dimethylamino)boryl,dimethylamino, diethylamino, 2-dimethylaminoethyl, 2-methoxyphenyl,3-methoxyphenyl, 4-methoxyphenyl, 2,6-dimethoxyphenyl,2,6-dimethoxy-4-methylphenyl, 2-dimethylaminophenyl, phenylamino,phenylmethylamino, acetamide, formylamino, benzamido, benzoyl,methylcarboxamide, dimethylcarboxamide, methoxymethyl, ethoxymethyl,phenoxymethyl, methoxyethyl, ethoxyethyl, phenoxyethyl,phospholanylmethyl, diethylphospholanylmethyl, 2-furanyl, 3-furanyl,pyrrolyl, imidazolyl, pyrrolidinyl, piperidinyl, pyridinyl, pyridazinyl,pyrazolidinyl, pyrazinyl, thienyl, thiazolyl, trimethylsilyl,trimethylsilylmethyl, dimethylphenylsilyl, methylsulfinyl,ethylsulfinyl, methylsulfonyl, ethylsulfonyl; or a substituted orunsubstituted heteroatom group having 1-6 non-hydrogen atoms, preferablya nitro group, one oxygen atom, or one sulfur atom, R₃ and R₄ preferablyare substituted or unsubstituted aryl or arylalkyl groups, morepreferably substituted or unsubstituted aryl groups. When two or moreR₃, R₄, or R₅ groups, independently selected, are linked together, themoiety they form is di- or polyvalent, depending on how many R₃, R₄, orR₅ groups are linked together. For example, if two R₃, R₄, or R₅ groupsare linked together, the moiety is divalent; if three R₃, R₄, or R₅groups are linked together, the moiety is trivalent. When two or moreR₃, R₄, or R₅ groups, independently selected, are linked together, thelinked R₃, R₄, or R₅ groups are not hydrogen, fluoro, chloro, bromo orcyano.

In some embodiments, ligating compounds of the present invention includethe following compositions:

and their enantiomers. Optionally from two to ten, preferably from twoto six, independently selected ligating compounds may be linked togethervia their respective independently selected Ar, Ar′, X″, Y, R₁, R₂, R₃,R₄ or R₅ groups to form a poly(ligating compound) species. Thepoly(ligating compound) species may take the form of dendrimers,oligomers or polymers of the ligating compound. The poly(ligatingcompound) species may be a linear, branched, or cyclic dendrimer,oligomer or polymer, wherein each monomer unit is an individualindependently selected ligating compound. In one embodiment all of theindividual ligating compounds are the same as each other. In oneembodiment the individual ligating compounds are not all the same aseach other.

The ligating compounds may be linked to form the poly(ligating compound)species by removing one or more independently selected atoms, preferablyone atom, from one or more of the respective independently selected Ar,Ar′, X″, Y, R₁, R₂, R₃, R₄ or R₅ groups of each ligating compound toprovide one or more free valencies on each ligating compound and thenlinking the ligating compounds having one or more free valencies to eachother at the free valence sites to form the poly(ligating compound). Inone embodiment the ligating compounds are linked via their correspondingindependently selected Ar, Ar′, X″, Y, R₁, R₂, R₃, R₄ or R₅ groups(e.g., R₁ from one ligating compound is linked with R₁ from anotherligating compound or Y from one ligating compound is linked with Y fromanother ligating compound). In one embodiment the ligating compounds arelinked, but not via their corresponding independently selected Ar, Ar′,S″, Y, R₁, R₂, R₃, R₄ or R₅ groups (e.g., R₂ from one ligating compoundis linked with a group from another ligating compound other than R₂).

Specific, but non-limiting, examples of the poly(ligating compound)include:

and their enantiomers.

Preparation of the Ligating Compounds

According to an even further aspect of the invention, there is provideda process to prepare a ligating compound, represented as:

as described above, the steps of the process comprising a) contactingapproximately one equivalent of

or silyl derivative thereof with approximately one equivalent of a

cyclic or acyclic precursor, or b) contacting approximately oneequivalent of

or silyl derivative thereof with approximately one equivalent of a

cyclic precursor; optionally in the presence of at least one equivalentof a proton scavenger; X is a leaving group; and optionally isolatingthe product.

The ligating compounds and subunits and precursor materials thereof, asrepresented in this section (“Preparation of the ligating compounds”)for the sake of brevity without the dashed connections depicting theoptional character of the linkages, may be prepared by any one ofseveral methods. In general, the method of preparation is selected basedon the nature of the subunits of the ligating compound, that is,

and the availability (commercial or through synthesis) of suitableprecursor materials. In general, the preparation may be achieved bycontacting a hydrogen-, halide- or other leaving group derivative, oralkali metal-, alkaline earth metal-, or alkaline earth metal-halidederivative of

with a suitable hydrogen-, halide- or other leaving group derivative, oralkali metal-, alkaline earth metal-, or alkaline earth metal-halidederivative of

optionally in the presence of a proton scavenger, such as an amine. Thehalide or other leaving group preferably is chloride, bromide, iodide,sulfate, sulfonate, such as methanesulfonate (mesylate),p-toluenesulfonate (tosylate), or trifluoromethanesulfonate (triflate),or carboxylate, such as acetate or benzoate. The alkali metal preferablyis lithium, sodium, or potassium. The alkaline earth metal is magnesiumor calcium, preferably magnesium. The alkaline earth metal-halidepreferably is magnesiumchloride, magnesiumbromide, or magnesiumiodide.

The

alkali-, alkaline earth, or alkaline earth metal-halide derivatives of

respectively, preferably may be prepared by combining

with a strong base comprising M, such as sodium hydride, potassiumhydride, methyllithium, butyllithium, potassium t-butoxide, potassiumt-amylate, dibutylmagnesium, butyloctylmagnesium, methylmagnesiumbromide, ethylmagnesium iodide, or isopropylmagnesium chloride, whereinM is an alkali metal, alkaline earth metal, or alkaline earthmetal-halide.

The proton scavenger preferably is a trihydrocarbylamine, such astriethylamine or ethyldiisopropylamine, or an aromatic amine, such aspyridine or lutidine. In the case that

is R₅N, and R₅NH₂ is used as the hydrogen derivative of

in the process to prepare the ligating compound, the proton scavengermay advantageously be R₅NH₂.

In an embodiment, the invention provides a process to prepare theligating compounds

similar to the manner of Nifant'ev et al. (“The synthesis and structureof phosphorus(III)-phosphoiylated 2-aminopyridines and theirderivatives”, Nifant'ev, E. E.; Negrebetskii, V. V.; Gratchev, M. K.;Kuroclikina, G. I.; Bekker, A. R.; Vasyanina, L. K.; Sakharov, S. G.,Phosphorus, Sulfur and Silicon and the Related Elements 1992, 66,261-71), the steps comprising contacting cyclic or acyclic groupprecursors such as halide-, sulfonate, or other leaving groupderivatives of

wherein X is a leaving group, preferably chloride, bromide, iodide,mesylate, tosylate, or triflate, more preferably chloride or iodide,even more preferably iodide, and further wherein

are selected according to the desired ligating compound to be obtained,with

wherein L-H independently is NH, PH, OH, or SH, and R′ independentlyselected is hydrogen, C₁₋₆ hydrocarbyl, or halide, preferably in thepresence of a proton scavenger. This embodiment allows the preparationof unsymmetrical ligating compounds, wherein

as well as symmetric ligating compounds, wherein

Not desiring to be bound to any particular method, the symmetricligating compound may be prepared by contacting approximately twoequivalents of the

cyclic precursor with approximately one equivalent of

in the presence of preferably at least two equivalents of a protonscavenger.

Not desiring to be bound to any particular method, the unsymmetricalligating compound, wherein

is obtained by first contacting preferably either approximately oneequivalent of

cyclic precursor or one equivalent of

acyclic precursor with preferably approximately one or more equivalentsof linking group precursor

or silyl derivative thereof, represented as

preferably in the presence of at least, one equivalent, preferably atleast five equivalents, more preferably at least ten equivalents of aproton scavenger in a first reaction to give a first product representedas

or silyl derivatives thereof, represented as

then contacting this first product with preferably approximately oneequivalent of the other selected

acyclic precursor preferably in the presence of at least one equivalent,more preferably five equivalents, even more preferably ten equivalentsof a proton scavenger. Preferably the linking group precursor

can serve as the proton scavenger in the first reaction to give thefirst product, wherein at least one additional equivalent, preferably atleast additional five equivalents, more preferably at least tenadditional equivalents of the linking group precursor are used,optionally in the presence of a proton scavenger, preferably atrihydrocarbylamine or aromatic amine.

In a less preferred (due to the greater statistical possibility offorming symmetric ligating compounds) embodiment for producing theunsymmetrical ligating compounds, the

cyclic precursor and the

cyclic or

acyclic precursor may be contacted concurrently with

in the presence of preferably at least two equivalents of a protonscavenger.

Preferably the

cyclic precursors are represented as

respectively, preferably

more preferably

wherein X is a leaving group, preferably halide, more preferablychloride or iodide, still more preferably

wherein L preferably is nitrogen or carbon, more preferably carbon; the

acyclic precursor is represented as

preferably

the linking group precursors

are represented as R₅NH₂ and R₅NH(SiR′₃), respectively;

or silyl derivatives thereof, represented as

are represented as

or silyl derivatives thereof, represented as

respectively, preferably as

respectively, wherein R₁, R₂, R₃, R₄, R₅, L, t, p, q, and n are asdescribed above; R′ independently selected is hydrogen, C₁₋₆hydrocarbyl, or halide; more preferably

wherein L is nitrogen or carbon, preferably L is carbon, preferably thephosphacycle is a 5-membered phospholane wherein both atoms directlybonded to P are sp³ hybridized and the phospholane is not8-aza-1-phosphatricylo[3.3.0.0^(2,6)]octane, more preferably representedas

wherein R₅, R′, and n are as described above.

In an embodiment, the invention provides a process for the preparationof a first product

the steps of the process comprising contacting preferably approximatelyone equivalent of

cyclic precursor with preferably approximately one or more equivalentsof linking group precursor

optionally in the presence of at least one equivalent, preferably atleast five equivalents, more preferably at least ten equivalents of aproton scavenger, and optionally isolating the product. Preferably thelinking group precursor

can serve as the proton scavenger in the first reaction to give thefirst product, wherein at least one additional equivalent, preferably atleast additional five equivalents, more preferably at least tenadditional equivalents of the linking group precursor are used,optionally in the presence of a proton scavenger, preferably atrihydrocarbylamine or aromatic amine.

Preferably the

cyclic precursor is represented as

wherein X is a leaving group, preferably

more preferably

still more preferably

even still more preferably

preferably the linking group precursor

are represented as R₅NH₂ or R₅NH(SiR′₃);

is represented as

preferably as

more preferably

even still more preferably

most preferably by

In an embodiment, the invention provides a process for the preparationof the ligating compound, the steps of the process comprising contactingpreferably approximately one equivalent of

with preferably approximately one equivalent of a

cyclic or acyclic precursor, preferably acyclic precursor, optionally inthe presence of at least one equivalent, more preferably fiveequivalents, even more preferably ten equivalents of a proton scavengerand optionally isolating the product. Preferably the

cyclic precursor is represented as

wherein X is a leaving group, preferably

more preferably

more preferably

still more preferably

even still more preferably

Preferably the

acyclic precursor is represented as

In an embodiment, the invention provides a process for the preparationof a first product

the steps of the process comprising contacting preferably approximatelyone equivalent of the

acyclic precursor with preferably approximately one or more equivalentsof linking group precursor

optionally in the presence of at least one equivalent, preferably atleast five equivalents, more preferably at least ten equivalents of aproton scavenger, and optionally isolating the product. Preferably thelinking group precursor

can serve as the proton scavenger in the first reaction to give thefirst product, wherein at least one additional equivalent, preferably atleast additional five equivalents, more preferably at least tenadditional equivalents of the linking group precursor are used,optionally in the presence of a proton scavenger, preferably atrihydrocarbylamine or aromatic amine.

Preferably the

acyclic precursor is represented as

preferably the linking group precursor

is represented as R₅NH₂ or R₅NH(SiR′₃); preferably

is represented as

In an embodiment, the invention provides a process for the preparationof the ligating compound, the steps of the process comprising contactingpreferably approximately one equivalent of

with preferably approximately one equivalent of a

cyclic precursor wherein X is a leaving group, optionally in thepresence of at least one equivalent, more preferably five equivalents,even more preferably ten equivalents of a proton scavenger andoptionally isolating the product. Preferably the cyclic precursor isrepresented as

preferably

more preferably

still more preferably

even still more preferably

In a non-limiting specific example, l-chloro-2,5-diphenylphospholane iscontacted with isopropylamine in the presence of triethylamine to givethe symmetric product N-isopropyl-[bis(2,5-diphenylphospholane)amine].

In a non-limiting specific example, l-chloro-2,5-diphenylphospholane iscontacted with ten equivalents of n-butylamine to giveN-butyl-(2,5-diphenylphospholane)amine as a first product, which iscontacted with chlorodiphenylphosphine in the presence of triethylamineto give N-butyl-(2,5-diphenylphospholane)(diphenylphosphino)amine.

In one embodiment of the process to prepare the ligating compounds,5-membered-ring analogs of the intermediate

cyclic precursor, represented as

may be prepared in an overall 7-step process as disclosed in a specificexample by combining Fox et al. (“Bis-(2,5-diphenylphospholanes) withsp² Carbon Linkers: Synthesis and Application in AsymmetricHydrogenation”, Fox, M. E.; Jackson, M.; Lennon, I. C.; Klosin, J.;Abboud, K. A. J. Org. Chem. 2008, 73, 775-784.) and Guillen et al.(“Synthesis and first applications of a new family of chiralmonophosphine ligand: 2,5-diphenylphospholanes”, Guillen, R; Rivard, M.;Toffano, M.; Legros, J.-Y.; Daran, J.-C.; Fiaua, J.-C. Tetrahedron 2002,58, 5895-5904) wherein 1,4-diphenylbutadiene is cyclized with Cl₂PNMe₂to give a first product which is hydrogenated to giveN,N-dimethyl-2,5-diphenyl-1-phospholanamine-1-oxide as a second product,the second product is isomerized to give a third product as anapproximately racemic mixture of R,R and S,S products. It requires foursteps (hydrolysis, Step 4; chlorination, Step 5; reduction, Step 6; andchlorination, Step 7) to convert the third product into the seventhproduct, the cyclic phosphine chloride:

In an embodiment, the invention provides an improved process to preparethe cyclic phosphine halide represented as

the steps of the process comprising contacting a cyclic phosphinic amiderepresented as

with at least one hydrido-silicon compound represented as R′₃SiH and atleast one silicon halide compound represented as R′₃SiX in the presenceof one or more bases, and optionally isolating the product. The improvedprocess provides the cyclic phosphine halide from the cyclic phosphinicamide in one chemical step, as represented below:

The intermediate cyclic phosphinic amide precursor (obtainable, for5-membered cyclic phosphinic amides according to Guillen et al. from thecorresponding 1,3-butadiene compound

is represented as:

preferably

more preferably

even more preferably

wherein R₅=hydrogen, aryl, substituted aryl, arylalkyl, or substitutedarylalkyl, preferably hydrogen, aryl, or substituted aryl, morepreferably at least two R₅ are aryl or substituted aryl and at least twoR₅ are hydrogen; and R″=alkyl, preferably C₁₋₆ alkyl, more preferablymethyl or ethyl; still more preferably

even more preferably

wherein R₅=aryl, substituted aryl, arylalkyl, or substituted arylalkyl,preferably aryl or substituted aryl; and R″ is methyl or ethyl, evenmore preferably

even still more preferably

corresponding to the product of Step 3 of the state-of-the-art processabove; the cyclic phosphine halide, preferably chloride, is representedas

preferably

more preferably

wherein X is halide, preferably chloride, bromide or iodide, morepreferably chloride or bromide, even more preferably chloride; R′independently selected is hydrogen, C₁₋₆ hydrocarbyl, or halide; R₅independently is hydrogen, C₁₋₂₀ aryl, C₁₋₂₀ substituted aryl, C₁₋₂₀arylalkyl, or C₁₋₂₀ substituted arylalkyl, preferably hydrogen, C₁₋₁₂aryl, C₁₋₁₂ substituted aryl, C₁₋₁₂ arylalkyl, or C₁₋₁₂ substitutedarylalkyl, more preferably C₁₋₁₂ aryl, or C₁₋₁₂ substituted aryl, morepreferably at least two R₅ are C₁₋₁₂ aryl or C₁₋₁₂ substituted aryl andat least two R₅ are hydrogen, still more preferably

wherein R₅═C₁₋₁₂ aryl, C₁₋₁₂ substituted aryl, C₁₋₁₂ arylalkyl, orsubstituted C₁₋₁₂ arylalkyl, preferably C₁₋₁₂ aryl or C₁₋₁₂ substitutedaryl, even more preferably

corresponding to the product of Step 7 of die state-of-the-art processabove; the at least one hydrido-silicon compound is represented asR′₃SiH and the at least one silicon halide compound is represented asR′₃SiX, wherein L, R₅, and t are as described above; R″ independentlyselected is hydrogen; C₁₋₂₀, preferably C₁₋₁₂, more preferably C₁₋₆,hydrocarbon derivative, preferably R″ is C₁₋₂₀, preferably C₁₋₁₂, morepreferably C₁₋₆, hydrocarbyl, more preferably C₁₋₁₂, more preferablyC₁₋₆, alkyl or C₁₋₂₀, more preferably C₂₋₁₂ aryl or arylalkyl, stillmore preferably methyl, ethyl, propyl, isopropyl, butyl, phenyl,preferably methyl, ethyl, isopropyl; R′ independently selected ishydrogen, C₁₋₂₀, preferably C₁₋₁₂, more preferably C₁₋₆, hydrocarbyl,C₁₋₂₀, preferably C-n, more preferably C₁₋₆, heterohydrocarbyl orhalide, e.g., chloride, bromide, iodide, preferably chloride or bromide,more preferably chloride; more preferably R′ is hydrogen, methyl, ethyl,propyl, butyl, allyl, vinyl, t-butyl, phenyl, tolyl, chloride, bromide,iodide, dimethylamido ((CH₃)₂N), diethylamide ((CH₃CH₂)₂N), methoxy,ethoxy, propoxy, phenoxy, more preferably hydrogen, chloride, methyl,ethyl, phenyl; X is chloride, bromide, iodide, preferably chloride; eachbase of the one or more bases is independently a hydrocarbylamine,preferably a hydrocarbylamine not having N—H bonds that interferesubstantially with the transformation of the intermediate cyclicphosphinic amide into the cyclic phosphine halide, preferably atrihydrocarbyl amine or an aromatic amine, preferably a C₁₋₁₂trihydrocarbylamine or a C₁₋₁₂ aromatic amine, more preferably triethylamine, ethyldiisopropylamine, pyridine, 2-methylpyridine,3-methylpyridine, 4-methylpyridine, lutidine, pyrimidine, pyrazole,dimethylphenylamine, N,N-dimethylaminopyridine,1,8-diazabicyclo[5.4.0]undec-7-ene, or methylimidazole, even morepreferably pyridine.

In a preferred embodiment, the at least one hydrido-silicon compound andthe at least one silicon halide compound is at least one hydrido-siliconhalide compound, preferably one hydrido-silicon halide compound,represented as R′₂SiHX. Preferably R′₃SiH is CH₃SiH₃, CH₃CH₂SiH₃,(C₂H₃)SiH₃, ((CH₃)₂CH)SiH₃, (CH₃CH₂CH₂)SiH₃, (CH₂CHCH₂)SiH₃,(CH₃CH₂CH₂CH₂)SiH₃, ((CH₃)₃C)SiH₃, C₆H₅SiH₃,CH₃CH₂CHCH₂CH₂CH₂CH₂CH₂SiH₃, H₃SiCH₂CH₂SiH₃, (CH₃)₂SiH₂, (CH₃CH₂)₂SiH₂,(CH₃)(C₂H₃)SiH₂, ((CH₃)₂CH)₂SiH₂, (CH₃CH₂CH₂)₂SiH₂, (CH₃CH₂CH₂CH₂)₂SiH₂,((CH₃)₃C)₂SiH₂, ((CH₃)₃C)(CH₃)SiH₂, (C₆H₅)(CH₃)SiH₂, (C₆H₅)₂SiH₂,(CH₃C₆H₄)₂SiH₂, H₂(CH₃)SiCH₂CH₂Si(CH₃)H₂, (CH₃)₃SiH, (CH₃CH₂)₃SiH,((CH₃)₂CH)₃SiH, (CH₃CH₂)(CH₃)₂SiH, ((CH₃)₂CH)(CH₃)₂SiH,(CH₂CHCH₂)(CH₃)SiH, (CH₃CH₂CH₂)₃SiH, (CH₃CH₂CH₂CH₂)₃SiH,(C₆H₅CH₂)(CH₃)₂SiH, (C₆H₅)₃SiH, (CH₃C₆H₄)₃SiH, (C₆H₅)(CH₃)₂SiH,(C₆H₅)₂(CH₃)SiH, (CH₃)₂(CH₂Cl)SiH, (CH₃)₂(C₂H₃)SiH,(CH₂CH₂)((CH₃)₂SiH)₂, ((CH₃)₃C)(CH₃)₂SiH, ((CH₃)₃C)₂(CH₃)SiH,((CH₃)₃C)(C₆H₅)₂SiH, H(CH₃)₂SiCH₂CH₂Si(CH₃)₂H((CH₃)₂SiH)₂O,((CH₃CH₂)₂SiH)₂O, ((CH₃)(C₆H)SiH)₂O, ((C₆H₅)₂SiH)₂O, ((CH₃)₂CH)₂SiH)₂Oor H₃SiSiH₃, more preferably CH₃SiH₃, CH₃CH₂SiH₃, ((CH₃)₂CH)SiH₃,((CH₃)₃C)SiH₃, C₆H₅SiH₃, (CH₃)₂SiH₂, (CH₃CH₂)₂SiH₂, ((CH₃)₂CH)₂SiH₂,((CH₃)₃C)₂SiH₂, ((CH₃)₃C)(CH₃)SiH₂, (C₆H₅)(CH₃)SiH₂, (C₆H₅)₂SiH₂,(CH₃C₆H₄)₂SiH₂, (CH₃)₃SiH, (CH₃CH₂)₃SiH, ((CH₃)₂CH)₃SiH, (C₆H₅)₃SiH,(CH₃C₆H₄)₃SiH, (C₆H₅)(CH₁)₂SiH, (C₆H₅)₂(CH₃)SiH, ((CH₃)₃C)(CH₃)₂SiH or((CH₃)₃C)₂(CH₃)SiH, even more preferably CH₃SiH₃, CH₃CH₂SiH₃,((CH₃)₂CH)SiH₃, C₆H₅SiH₃, (CH₃)₂SiH₂, (CH₃CH₂)₂SiH₂, ((CH₃)₂CH)₂SiH₂,((CH₃)₃C)₂SiH₂, (C₅H₅)₂SiH₂, (CH₃)₃SiH, (CH₃CH₂)₃SiH, ((CH₃)₂CH)₃SiH or(C₆H₅)₃SiH, still more preferably CH₃SiH₃, C₆H₅SiH₃, (CH₃)₂SiH₂,(C₆H₅)₂SiH₂, (CH₃)₃SiH or (C₅H₅)₃SiH; preferably R′₃SiX is CH₃SiCl₃,CH₃CH₂SiCl₃, (C₂H₃)SiCl₃, ((CH₃)₂CH)SiCl₃, (CH₃CH₂CH₂)SiCl₃,(CH₂CHCH₂)SiCl₃, (CH₃CH₂CH₂CH₂)SiCl₃, ((CH₃)₃C)SiCl₃, C₆H₅SiCl₃,CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂SiCl₃, Cl₃SiSiCl₃, Cl₃SiCH₂CH₂SiCl₃,(CH₃)₂SiCl₂, (CH₃CH₂)₂SiCl₂, (CH₃)(C₂H₃)SiCl₂, ((CH₃)₂CH)₂SiCl₂,(CH₃CH₂CH₂)₂SiCl₂, (CH₃CH₂CH₂CH₂)₂SiCl₂, ((CH₃)₃C)₂SiCl₂,((CH₃)₃C)(CH₃)SiCl₂, (C₆H₅)(CH₃)SiCl₂, (C₆H₅)₂SiCl₂, (CH₃C₆H₄)₂SiCl₂,Cl₂(Cl₃)SiCH₂CH₂Si(CH₃)Cl₂, (CH₃)₃SiCl, (CH₃)₃SiI, (CH₃CH₂)₃SiCl,((CH₃)₂CH)₃SiCl, (CH₃CH₂)(CH₃)₂SiCl, ((CH₃)₂CH)(CH₃)₂SiCl,(CH₂CHCH₂)(CH₃)₂SiCl, (CH₃CH₂CH₂)₃SiCl, (CH₃CH₂CH₂CH₂)₃SiCl,(C₆H₅CH₂)(CH₃)₂SiCl, (C₆H₅)₃SiCl, (CH₃C₆H₄)₃SiCl, (C₆H₅)(CH₃)₂SiCl,(C₆H₅)₂(CH₃)SiCl, (CH₃)₂(CH₂Cl)SiCl, (CH₃)₂(C₂H₃)SiCl,(CH₂CH₂)((CH₃)₂SiCl)₂, ((CH₃)₃C)(CH₃)₂SiC, ((CH₃)₃C)₂(CH₃)SiCl,((CH₃)₃C)(C₆H₅)₂SiCl, Cl(CH₃)₂SiCH₂CH₂Si(CH₃)Cl((CH₃)₂SiCl)₂O,((CH₃CH₂)₂SiCl)₂O, ((CH₃)(C₆H₅)SiCl)₂O, ((C₆H₅)₂SiCl)₂O or((CH₃)₂CH)₂SiCl)₂O, more preferably CH₃SiCl₃, CH₃CH₂SiCl₃,((CH₃)₂CH)SiCl₃, ((CH₃)₃C)SiCl₃, C₆H₅SiCl₃, (CH₃)₂SiCl₂, (CH₃CH₂)₂SiCl₂,((CH₃)₂CH)₂SiCl₂, ((CH₃)₃C)₂SiCl₂, ((CH₃)₃C)(CH₃)SiCl₂,(C₆H₅)(CH₃)SiCl₂, (C₆H₅)₂SiCl₂, (CH₃C₆H₄)₂SiCl₂, (CH₃)₃SiCl, (CH₃)₃SiI,(CH₃CH₂)₃SiCl, ((CH₃)₂CH)₃SiCl, (C₆H₅)₃SiCl, (CH₃C₆H₄)₃SiCl,(C₆H₅)(CH₃)₂SiCl, (C₆H₅)₂(CH₃)SiCl, ((CH₃)₃C)(CH₃)₂SiCl or((CH₃)₃C)₂(CH₃)SiCl, even more preferably CH₃SiCl₃, (CH₃)₃SiI,CH₃CH₂SiCl₃, ((CH₃)₂CH)SiCl₃, C₆H₅SiCl₃, (CH₃)₂SiCl₂, (CH₃CH₂)₂SiCl₂,((CH₃)₂CH)₂SiCl₂, ((CH₃)₃C)₂SiCl₂, (C₆H₅)₂SiCl₂, (CH₃)₃SiCl,(CH₃CH₂)₃SiCl, ((CH₃)₂CH)₃SiCl or (C₆H₅)₃SiCl, still more preferablyCH₃SiCl₃, (CH₃)₃SiI, C₆H₅SiCl₃, (CH₃)₂SiCl₂, (C₆H₅)₂SiCl₂, (CH₃)₃SiCl,(C₆H₅)₃SiCl; preferably R′₂SiHX is HSiCl₃, H₂SiCl₂, H₃SiCl, (CH₃)₂SiHCl,(CH₃CH₂)₂SiHCl, (CH₂CH)₂SiHCl, ((CH₃)₂CH)₂SiHCl, (CH₃CH₂CH₂)₂SiHCl,(CH₃CH₂CH₂CH₂)₂SiHCl, ((CH₃)₃C)₂SiHCl, ((CH₃)₃C)(CH₃)SiHCl,(C₆H₅)(CH₃)SiHCl, (C₆H₅)₂SiHCl, (CH₃C₆H₄)₂SiHCl,Cl(CH₃)HSiCH₂CH₂SiH(CH₃)Cl, CH₃SiHCl₂, CH₃CH₂SiHCl₂, (C₂H₃)SiHCl₂,((CH₃)₂CH)SiHCl₂, (CH₃CH₂CH₂)SiHCl₂, (CH₂CHCH₂)SiHCl₂,(CH₃CH₂CH₂CH₂)SiHCl₂, ((CH₃)₃C)SiHCl₂, C₆H₅SiHCl₂, Cl₂HSiCH₂CH₂SiHCl₂,Cl₂HSiSiHCl₂, CH₃SiH₂Cl, CH₃CH₂SiH₂Cl, (C₂H₃)SiH₂Cl, ((CH₃)₂CH)SiH₂Cl,(CH₃CH₂CH₂)SiH₂Cl, (CH₂CHCH₂)SiH₂Cl, (CH₃CH₂CH₂CH₂)SiH₂Cl,((CH₃)₃C)SiH₂Cl, C₆H₅SiH₂Cl, ClH₂SiCH₂CH₂SiH₂Cl or ClH₂SiSiH₂Cl, morepreferably HSiCl₃, H₂SiCl₂, (CH₃)₂SiHCl, (CH₃CH₂)₂SiHCl,((CH₃)₂CH)₂SiHCl, ((CH₃)₃C)₂SiHCl, ((CH₃)₃C)(CH₃)SiHCl,(C₆H₅)(CH₃)SiHCl, (C₆H₅)₂SiHCl, CH₃SiHCl₂, CH₃CH₂SiHCl₂,((CH₃)₂CH)SiHCl₂, ((CH₃)₃C)SiHCl₂, C₆H₅SiHCl₂, CH₃SiH₂Cl, CH₃CH₂SiH₂Cl,((CH₃)₂CH)SiH₂Cl, ((CH₃)₃C)SiH₂C₁ or C₆H₅SiH₂Cl, even more preferablyHSiCl₃, H₂SiCl₂, (CH₃)₂SiHCl, (C₆H₅)(CH₃)SiHCl, (C₆H₅)₂SiHCl, CH₃SiHCl₂,C₆H₅SiHCl₂, CH₃SiH₂Cl or C₆H₅SiH₂Cl, still more preferably HSiCl₃,H₂SiCl₂, (CH₃)₂SiHCl, (C₆H₅)₂SiHCl or CH₃SiHCl₂, HSiCl₃ is most highlypreferred. Mixtures of the foregoing may also be used.

In an embodiment of the one-step improved process to convert theintermediate cyclic phosphinic amide into the cyclic phosphine halideproduct using R′₃SiH, R′₃SiX or R′₂SiHX compounds, the cyclic phosphinehalide product can be separated or purified from the silicon-containingco-products which result by extracting or partitioning the cyclicphosphine halide into the high polarity solvent phase of a high polaritysolvent/low polarity two-phase solvent mixture and extracting orpartitioning the silicon-containing co-products into the low polaritysolvent phase of a two-phase high polarity solvent/low polarity solventmixture, preferably wherein the high polarity solvent phase comprisesone or more solvents selected from C₂₋₈ nitriles, such as acetonitrile,propanenitrile, butanenitrile, benzenenitrile; C₁₋₁₀ amides, such asformamide, N,N-dimethylformamide, N,N-diethylformamide,N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylbenzamide; C₁₋₈carboxylic acids, such as formic acid, acetic acid, propanoic acid,butanoic acid, malonic acid; C₁₋₈ alcohols, such as methanol, ethanol,propanol, isopropanol, n-butanol, t-butanol; dimethylsulfoxide;preferably acetonitrile, propanenitrile, formamide,N,N-dimethylformamide, N,N-dimethylacetamide, acetic acid ordimethylsulfoxide, more preferably acetonitrile, and the low polaritysolvent phase comprises one or more solvents selected from C₆₋₁₂aromatic hydrocarbons, C₄₋₁₂ saturated hydrocarbons or C₄₋₁₀ ethers,preferably C₄₋₈ saturated hydrocarbons, C₆₋₈ aromatic hydrocarbons orC₆₋₈ ethers, more preferably butane, pentane, cyclopentane, hexane,cyclohexane, methylcyclopentane, heptane, methylcycloheptane, octane,2,2,4,-trimethylpentane, benzene, toluene, diisopropyl ether or dibutylether, even more preferably butane, pentane, hexane, still morepreferably pentane. Preferably the two-phase high polarity solvent/lowpolarity solvent mixture components are selected such that the highpolarity solvent and the low polarity solvent are immiscible in eachother, such that a two-phase solvent mixture is provided, e.g.,pentane/acetonitrile, diethyl ether/dimethylsulfoxide,hexane/dimethylformamide. After the cyclic phosphine halide and thesilicon-containing co-product mixture has been extracted or partitionedin the high polarity solvent/low polarity solvent mixture and the highpolarity and low polarity solvent phases have been separated, the cyclicphosphine halide can be recovered by methods known to one of ordinaryskill in the art, such as evaporating off the solvent. Alternatively thecyclic phosphine halide product can be separated or purified from thesilicon-containing co-products by washing the cyclic phosphinehalide/silicon-containing co-product mixture with one or more lowpolarity solvents, preferably pentane, hexane, heptane or cyclohexane,more preferably pentane. Preferably the cyclic phosphine halide productis purified by partitioning the cyclic phosphine chloride and reactioncoproducts in a two-phase acetonitrile/hexane solvent mixture.

This improved process for the conversion of the intermediate cyclicphosphinic amide into the cyclic phosphine halide reduces the number ofsteps required from four to one.

In one embodiment of the process to prepare die ligating compounds,similar to the manner of Fox et at, halide- or other leaving groupderivatives of

wherein X is a leaving group, are contacted with

wherein L-H independently is CH, NH, PH, OH, or SH, to prepare thedesired ligating compound

respectively. This embodiment allows the preparation of unsymmetricalligating compounds, wherein

as well as symmetric ligating compounds, wherein

Not desiring to be bound to any particular method, the symmetricligating compound may be prepared by combining approximately twoequivalents of the

cyclic precursor with approximately one equivalent of

whereas the unsymmetrical ligating compound, wherein

is preferably obtained by first combining either approximately oneequivalent of

cyclic precursor or approximately one equivalent of

cyclic or

acyclic precursor with approximately one equivalent of

then combining the product of the just-mentioned first reaction with astrong base comprising M to form

respectively, which is then contacted with either approximately oneequivalent of a different

cyclic precursor or approximately one equivalent of a different

cyclic or

acyclic precursor. The

intermediates may also be formed by combination of approximately oneequivalent of

with approximately one equivalent of

cyclic precursor or approximately one equivalent of

cyclic or

acyclic precursor

In another non-limiting embodiment of the process to prepare theligating compounds,

wherein

may be selected according to the desired ligating compound to beobtained, may be contacted with a halide or other leaving groupderivative of

such as

in the presence of preferably at least two equivalents of a protonscavenger to give the ligating product. As above, symmetric orunsymmetrical products may be obtained by choice of stoichiometry andprecursors. Such chemistry is analogous to that disclosed in Montag etal. (“The unexpected role of CO in C—H oxidative addition by a cationicrhodium(I) complex”, Montag, M.; Schwartsburd, L.; Cohen, R.; Leitus, G;Ben-David, Y.; Martin, J. M. L.; Milstein, D., Angew. Chem., Int. Ed.2007, 46, 1901-1904) wherein 1,3-bis(bromomethyl)benzene anddiisopropylphosphine are contacted with triethylamine to prepare1,3-bis(diisopropylphosphinomethyl)benzene.

In another non-limiting embodiment of the process to prepare theligating compounds, a halide- or other leaving group derivative of

such as

preferably when the leaving group is attached to L when L is P, C, Si,Ge, or B, may be contacted with an alkali metal-, alkaline earth metal-,or alkaline earth metal-halide derivative of

such as

to give the ligating product. As above, symmetric or unsymmetricalproducts may be obtained by choice of stoichiometry and precursors. Anon-limiting specific example of this embodiment of the process toprepare the ligating compounds is disclosed in Coleman et al.(“Coordination chemistry of cis,cis and trans,trans1,1′-[1,2-phenylenebis(methylene)]bis(2,2,3,4,4-pentamethylphosphetane)”Coleman. D.; Edwards, P. G.; Kariuki, B. M.; Newman, P. D. Dalton Tram.2010, 39, 3842-3850), wherein the lithium derivative of2,2,3,4,4-pentamethylphosphetane trihydroboron is contacted with1,2-bis(chloromethyl)benzene and the resulting product is treatedsequentially with HBF₄ and NaHCO₃ to give1,1′-[1,2-phenylenebis(methylene)]bis-(2,2,3,4,4-pentamethylphosphetane).

In another non-limiting embodiment of the process to prepare theligating compounds, silyl derivatives of

may be contacted with

acyclic precursors, wherein X is a leaving group, preferably chloride,bromide, iodide, mesylate, tosylate, or triflate, preferably chloride oriodide; preferably at least one L is N or O, preferably N, such thatL-SiR′₃ is N—SiR′₃ or O—SiR′₃, preferably N—SiR′₃. A non-limitingspecific example of the reaction to form a P—N bond by combining a P—Clbond-containing compound with a N-silyl bond-containing compound isdisclosed in Bettermann et al. (“Reaction of N- or O-trimethylsilylatedethanolamine derivatives with phosphorus(III)-halogen compounds.Intramolecular donor-acceptor interactions in compoundsCH₃OCH₂CH₂N(CH₃)PCl₂, (CH₃)₂NCH₂CH₂OPCl₂, (CH₃)₂NCH₂CH₂N(CH₃)P(C₆H₅)₂,(CH₃)₂NCH₂CH₂N(CH₃)P(C₆H₅)Cl, and (CH₃)₂NCH₂CH₂N(CH₃)PCl₂” Bettermann,G.; Schomburg, D.; Schmutzler, R. Phosphorus Sulfur Related Elements1986, 28, 327-336), whereinN¹N¹N²-trimethyl-N²-(trimethylsilyl)-1,2-ethanediamine is contacted withchlorodiphenylphosphine to give(2-(dimethylamino)ethyl(methyl)amino)diphenylphosphine.

In an embodiment of the invention, a process is provided represented as

and silyl derivatives thereof, represented as

as described above, more preferably represented as

or silyl derivatives thereof, represented as

respectively, preferably as

respectively, wherein R₁, R₂, R₃, R₄, R₅, L, t, p, q, and n are asdescribed above; R′ independently selected is hydrogen, C₁₋₆hydrocarbyl, or halide; more preferably

and the phosphacycle is not 8-aza-1-phosphatricylo[3.3.0.0^(2,6)]octane;preferably L is nitrogen or carbon, more preferably L is carbon; evenmore preferably

the phosphacycle is not 8-aza-1-phosphatricylo [3.3.0.0^(2,6)]octane;preferably L is nitrogen, preferably the phosphacycle is a 5-memberedphospholane wherein both atoms directly bonded to P are sp³ hybridizedand the phospholane is not 8-aza-1-phosphatricylo[3.3.0.0^(2,6)]octane,more preferably represented as

wherein R₅, R′, and n are as described above.

In one embodiment of the process to prepare the ligating compounds, theleaving group of the cyclic or acyclic phosphine precursor is chloride,bromide, iodide, mesylate, tosylate, or trifluoromethanesulfonate,preferably chloride or iodide, more preferably chloride. In oneembodiment of the above methods to produce the ligating compound or anyof the intermediate compounds, the cyclic or acyclic phosphine precursoris a cyclic or acyclic phosphine chloride which is advantageouslyemployed due to its ready availability, either commercially or throughsynthesis. In another embodiment of the above methods to produce theligating compound or any of the intermediate compounds, the cyclic oracyclic phosphine precursor is a cyclic or acyclic phosphine iodidewhich is preferred in some embodiments over the corresponding cyclic oracyclic phosphine chloride due to its greater reactivity with N—H orN—Si bonds. In one embodiment of the process to prepare the ligatingcompounds, the cyclic or acyclic phosphine chloride may be convertedinto the corresponding cyclic or acyclic phosphine iodide, the processcomprising contacting the cyclic phosphine chloride with an iodidesource wherein the iodide source is selected from the group comprisingLiI, NaI, KI, MgI₂, CaI₂, SmI₂(THF)₂, R′″₄NI, R′″₃SiI, R′″SiI₂, R′″SiI₃,and SiI₄, wherein THF is tetrahydrofuran, R′″ independently selected ishydrogen; C₁₋₂₀, preferably C₁₋₁₂, more preferably C₁₋₆ hydrocarbyl,preferably C₁₋₁₂, more preferably C₁₋₆, alkyl or C₂₋₂₀, more preferablyC₂₋₁₂ aryl or arylalkyl, still more preferably methyl, ethyl, isopropyl,t-butyl, phenyl, tolyl, benzyl, preferably methyl, t-butyl, and phenyl,and isolating the cyclic or acyclic phosphine iodide product. Preferablythe iodide source is trimethylsilyl iodide.

In another non-limiting embodiment of the process to prepare theligating compounds, the preparation of the ligating compound may beachieved by combining

wherein X₁H₂ is either PH₂ or NH₂, with a) a strong base comprising M,and with b) leaving group-containing derivatives of

R₃ or R₄, such as cyclic sulfate derivatives, such as

or sulfonate derivatives, such as

R₃-sulfonate or R₄-sulfonate, preferably wherein sulfonate is mesylate,tosylate, or triflate; or halide derivatives, such as

R₃-halide, or R₄-halide, wherein the halide is Cl, Br, or I;

is a divalent moiety in which R₁ and R₂ are linked together and

is a divalent moiety in which R₃ and R₄ are linked together. Anon-limiting specific example of this embodiment of the process toprepare the ligating compounds is disclosed in Bonnaventure et al.(“Probing the Importance of the Hemilabile Site of Bis(phosphine)Monoxide Ligands in the Copper-Catalyzed Addition of Diethylzinc toN-Phosphinoylimines: Discovery of New Effective Chiral Ligands”Bonnaventure, I.; Charette, A. B. J. Org. Chem., 2008, 73, 6330-6340),wherein 1,2-bis(phosphino)benzene is contacted with butyllithium and2,5-dimethyl-1,3,2-dioxathiepane 2,2-dioxide to give1,1′-(1,2-phenylene)bis[2,5-dimethylphospholane].

As is known to one skilled in the art, the yield and purity of theligating compound may be dependent to some extent on the reactionconditions, such as the temperature, the solvents employed, and theorder of addition in which the precursors are contacted with each other.Some minor experimentation, such as is known to be undertaken by oneskilled in the art, may be desirable for optimization of the yield andpurity, for example, in some cases it may be desirable to use any one ormore of the reaction components in excess, such as 0.01 to 0.5-foldexcess, or 0.5-5-fold excess, even as high as, or higher than 5-20-foldexcess, in order to increase the rate of the reaction and to improve theconversion.

In an embodiment of the invention the poly(ligating compound) may beprepared using coupling reactions to link two or more ligating compoundstogether. For example, Suzuki cross-coupling reactions can couple aligating compound having an organoboronic acid group with a ligatingcompound having an organohalide group. An example of the couplingreaction between a compound having an arylboronic acid group with acompound having an arylhalide group is described in Song et al.,(“Palladium catalyzed Suzuki-Miyaura coupling with aryl chlorides usinga bulky phenanthryl N-heterocyclic carbene ligand”, Song. C.; Ma, Y.;Chai, Q.; Ma, C.; Jiang, W.; Andrus, M. B. Tetrahedron, 2005, 61,7438-7446.) As described above in an embodiment, ligating compounds maybe prepared beginning with dihydrocarbylphosphine halide compounds. Inan embodiment, ligating compounds having an arylhalide group may beprepared beginning with a diarylphosphine halide having an arylhalidegroup which themselves can be prepared as described by De Pater et al(“(Perfluoro)alkylsilyl-Substituted 2-[Bis(4-aryl)phosphino]pyridines:Synthesis and Comparison of Their Palladium Complexes inMethoxycarbonylation of Phenylacetylene in Regular Solvents andSupercritical CO₂”, De Pater, J. J. M.; Maljaars, C. E. P.; De Wolf, E.;Lutz, M.; Spek, A. L.; Deelman, B.-J.; Elsevier, C. J.; Van Koten, G.Organometallics 2005, 24, 5299-5310.) In an embodiment, ligatingcompounds having an arylboronic acid group may be prepared by contactinga ligating compound having an arylhalide group with butyllithium, thenwith a boronic ester. The general reaction for preparing an arylboronicacid compound from an arylhalide in this manner has been described byMoleele et al. (“Methodology for the synthesis of 1,2-disubstitutedarylnaphthalenes from α-tetralones”, Moleele, S. S.; Michael, J. P.; DeKoning, C. B. Tetrahedron 2006, 62, 2831-2844.)

As described above in an embodiment, ligating compounds may be preparedby contacting a primary amine with cyclic and/or acyclic phosphinehalide precursors. In an embodiment related thereto, the poly(ligatingcompound) species can be prepared by contacting a compound having two ormore primary amine groups, such as 1,6-diaminohexane, with cyclic oracyclic phosphine halide precursors.

Ligating Compound-Chromium Complexes

In some, embodiments, the invention provides a ligating compound-metalcomplex which is useful in catalysis, especially in hydroformylation,isomerization, hydrogenation, polymerization processes, especially theoligomerization of olefins such as ethylene. In some embodiments, theinvention provides a ligating compound-chromium complex which is usefulin the oligomerization of olefins such as ethylene. The ligatingcompound-chromium complex is a composition comprising a) a source ofchromium and b) a phosphacycle-containing ligating compound as describedherein.

While not wishing to be bound by any particular theory or physicaldescription of the complex, it is believed that the ligating compound isbound to the chromium atom in the ligating compound-chromium complex ina bidentate fashion, but it is within the scope of the invention toenvision other modes of bonding in addition to bidentate ligand bonding.

The ligating compound-chromium complex R₁R₂P—Y—X₁R₃(R₄)_(m)[Cr] may berepresented as

wherein:P is phosphorus; X₁ is selected from nitrogen, phosphorus, oxygen, orsulfur; each of R₁ and R₂ is independently a substituted orunsubstituted hydrocarbon derivative, a substituted or unsubstitutedheterohydrocarbon derivative, or a substituted or unsubstitutedheteroatom group having from one to 50 non-hydrogen atoms; m is 0 or 1;R₁ and R₂ are linked together to form a divalent moiety represented as

which together with P forms a cyclic structure (phosphacycle) containingfrom 3 to 10 ring atoms; each of R₃ and R₄ is independently hydrogen,halogen, a substituted or unsubstituted hydrocarbon derivative, asubstituted or unsubstituted heterohydrocarbon derivative, or asubstituted or unsubstituted heteroatom group having from one to 50non-hydrogen atoms; R₃ and R₄ are optionally linked together to form adivalent moiety represented as

wherein the optional character or the linkage is depicted by a dashedconnection, which together with X₁ forms a cyclic structure containingfrom 3 to 10 ring atoms; [Cr] comprises a chromium atom from the sourceof chromium along with any ancillary ligands, that is, the ligandsattached to the chromium atom not including the ligating compound; Y,optionally linked together with one or more of R₁, R₂, R₃, or R₄ to formcyclic structures containing from 4 to 10 ring atoms, as represented by:

wherein the optional character of the linkages is depicted by a dashedconnection, is a divalent linking group [L(R₅)_(q)]_(p) between P and X₁containing from one to 50 non-hydrogen atoms; [L(R₅)_(q)]_(p) isrepresented by:

wherein each L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur; p is an integer number from 1 to 6, preferably from 1 to 4; R₅is independently hydrogen, halogen, substituted or unsubstitutedhydrocarbon derivative, substituted or unsubstituted heterohydrocarbonderivative, or a substituted or unsubstituted heteroatom group; q is 0,1, or 2; provided that the [L]_(p) subunit of the divalent linking group[L(R₅)_(q)]_(p) does not comprise an amidine (N—C═N) group; furtherprovided that in at least one phosphacycle of thephosphacycle-containing ligating compound-chromium complex, both atomsdirectly bonded to P or X₁ are sp³ hybridized; still further preferablyprovided that one or two phosphacycles comprising P or X₁, preferablycomprising P, R₁, and R₂, or comprising X₁, R₃, and R₄, contain no P—N,P—O, or P—S bonds within the ring part of the phosphacycle; two or moreR₅ groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;from two to ten, preferably from two to six, independently selectedligating compound-chromium complexes may be optionally linked togethervia their respective independently selected Y, R₁, R₂, R₃, R₄ or R₅groups to form a poly(ligating compound-chromium complex) species.Preferably at least one, preferably two, phosphacycles do not containmore than one carbon-carbon unsaturated bond in each phosphacycle,preferably not more than one unsaturated bond in each phosphacycle.

The phosphacycle-containing ligating compound-chromium complex may bepresent as a monomer, represented as:

or as a dimer, represented as:

wherein [Cr]----[Cr] represents the two [Cr] groups and the linkagebetween them in the dimer form of the Ligating compound-chromiumcomplex.

In an embodiment of the invention, the invention comprises aphosphacycle-containing ligating compound-chromium complex (“ligatingcompound-chromium complex”) as represented by:

wherein P is phosphorus; X₁ is selected from nitrogen, phosphorus,oxygen, or sulfur, preferably nitrogen or phosphorus, more preferablyphosphorus; m is 0 or 1; each L is independently selected from boron,carbon, silicon, germanium, nitrogen, phosphorus, oxygen, or sulfur,preferably carbon, nitrogen, phosphorus, oxygen, or sulfur, morepreferably carbon or nitrogen; R₁ and R₂ are each independently selectedfrom substituted or unsubstituted hydrocarbon derivatives, substitutedor unsubstituted heterohydrocarbon derivatives, or a substituted orunsubstituted heteroatom group; R₁, P, and R₂ together form aphosphacycle; when R₃, R₄, and X₁ are linked together, they form aphosphacycle when X₁ is phosphorus and they form an azacycle when X₁ isnitrogen; two or more R₁, R₂, R₃, R₄ or R₅ groups are optionally linkedtogether to form cyclic structures containing from 4 to 10 ring atoms,preferably from 4 to 7 ring atoms wherein the optional character of thelinkages is depicted by a dashed connection; two or more R₅ groupsindependently are linked together with at least one L atom to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; two R₅ groups attached to the same L atom may beoptionally linked together to form a cyclic structure that contains from3 to 10 ring atoms, preferably from 3 to 7 ring atoms; optionally fromtwo to ten, preferably from two to six, independently selected ligatingcompound-chromium complexes may be linked together via their respectiveindependently selected R₁, R₂, R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species; R₃, R₄, and R₅ areeach independently selected from hydrogen, halogen, substituted orunsubstituted hydrocarbon derivatives, substituted or unsubstitutedheterohydrocarbon derivatives, or a substituted or unsubstitutedheteroatom group; p is an integer number from 1 to 6, preferably from 1to 4, more preferably from 1 to 3, most preferably from 1 to 2; q is 0,1, or 2; provided that the [L]_(p) subunit of the divalent linking group

does not comprise an amidine (N—C═N) group; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; still furtherpreferably provided that one or two phosphacycles comprising P or X₁,preferably comprising P, R₁, and R₂, or comprising X₁, R₃, and R₄,contain no P—N, P—O, or P—S bonds within the ring part of thephosphacycle. Preferably at least one, preferably two, phosphacycles donot contain mom than one carbon-carbon unsaturated bond in eachphosphacycle, preferably not more than one unsaturated bond in eachphosphacycle. Phosphacycles or azacycles are ring or cyclic compoundscomprising at least one phosphorus or nitrogen atom, respectively, inthe ring or cycle.

Each R₁ and R₂ independently contains from 1 to 50 non-hydrogen atoms;each R₃, R₄, and R₅ independently contains from 0 to 50 non-hydrogenatoms; preferably each R₅ independently contains from 0 to 40non-hydrogen atoms, more preferably from 0 to 20 non-hydrogen atoms, andmost preferably from 0 to 12 non-hydrogen atoms; optionally, at leastone R₅ group is a divalent group bonded to L via a double bond.

Preferably the phosphacycle-containing ligating compound-chromiumcomplex is represented by

wherein q is 0, 1, or 2; p is 1, 2, 3, or 4; t is 0, 1, 2, 3, or 4; v is0, 1, 2, 3, or 4; m is 0 or 1; L, R₃, R₁, R₅, and X₁ are as definedabove; further provided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species.

Preferably X₁ is nitrogen or phosphorus; p=1, 2, 3, or 4; q=0, 1 or 2; vand t are each independently 1, 2, 3, or 4; R₅ are each independentlyhydrogen; halogen; C₁₋₄₀ substituted or unsubstituted hydrocarbonderivative, preferably C₁₋₂₀ substituted or unsubstituted hydrocarbonderivative, more preferably C₁₋₁₂ substituted or unsubstitutedhydrocarbon derivative; C₁₋₄₀ substituted or unsubstitutedheterohydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms; R₃ and R₄ are each independently C₁₋₄₀ substituted orunsubstituted hydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted hydrocarbon derivative, more preferably C₁₋₁₂ substitutedor unsubstituted hydrocarbon derivative; C₁₋₄₀ substituted orunsubstituted heterohydrocarbon derivative, preferably C₁₋₂₀ substitutedor unsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms, more preferably one atom; when X₃ and its two attached R₃ and R₄groups form a cycle represented as:

the cycle is an azacycle when X₁ is nitrogen and a phosphacycle when X₁is phosphorus; P and its two attached R₁ and R₂ groups form aphosphacycle represented as:

Preferably the L atoms of the phosphacycle or azacycle are eachindependently carbon, nitrogen, or oxygen; [L(R₅)_(q)]_(p) is as definedabove. Preferably all L atoms of either phosphacycle which are directlyattached to the phosphorus of the phosphacycle are carbon;[L(R₅)_(q)]_(p) is as defined above. Preferred phosphacycle-containingligating compound-chromium complexes are represented by:

wherein [L(R₅)_(q)] of the phosphacycle or azacycle independentlyselected is C(R₅), O, N, N(R₅), or C(R₅)₂; [L(R₅)_(q)]_(p) is as definedabove; q is 0, 1, or 2; p is 1, 2, 3, or 4; t is 1, 2, 3, or 4; v is 1,2, 3, or 4; m is 0 or 1, X₁ is nitrogen, phosphorus, or oxygen,preferably nitrogen or phosphorus, more preferably phosphorus; R₅ areeach independently hydrogen; halogen; C₁₋₄₀ substituted or unsubstitutedhydrocarbon derivative, preferably C₁₋₂₀ substituted or unsubstitutedhydrocarbon derivative, more preferably C₁₋₁₂ substituted orunsubstituted hydrocarbon derivative; C₁₋₄₀ substituted or unsubstitutedheterohydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms; R₃ and R₄ are each independently C₁₋₄₀ substituted orunsubstituted hydrocarbon derivative, preferably C₁₋₂₀ substituted orunsubstituted hydrocarbon derivative, more preferably C₁₋₁₂ substitutedor unsubstituted hydrocarbon derivative; C₁₋₄₀ substituted orunsubstituted heterohydrocarbon derivative, preferably C₁₋₂₀ substitutedor unsubstituted heterohydrocarbon derivative, more preferably C₁₋₁₂substituted or unsubstituted heterohydrocarbon derivative; or aheteroatom group having one to four atoms, preferably one to threeatoms, more preferably one atom; further provided that in at least onephosphacycle of the phosphacycle-containing ligating compound, bothatoms directly bonded to P or X₁ are sp hybridized; two or more R₃, R₄or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms, preferably from 4 to 7 ring atoms;two or more R₅ groups independently are linked together with at leastone L atom to form a cyclic structure that contains from 3 to 10 ringatoms, preferably from 3 to 7 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; optionally from two to ten, preferably from two to six,independently selected ligating compound-chromium complexes may belinked together via their respective independently selected R₃, R₄ or R₅groups to form a poly(ligating compound-chromium complex) species. Morepreferably p=1 or 2. More preferably all [L(R₅)_(q)] groups of eitherphosphacycle which are directly attached to the phosphorus of thephosphacycle are independently C(R₅) or C(R₅)₂.

The number of chiral ring atoms, not including the P or X₁ attached to[L(R₅)_(q)]_(p), in each of the 4-, 5-, 6-, and 7-membered phosphacycleor azacycle rings in the ligating compound-chromium complex can rangefrom zero (none) up to one less than the number of ring atoms in eachring. In some embodiments, no carbon atoms in either of the one or two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, only one carbon atom in the one or two 4-, 5-, 6-, and7-membered phosphacycle or azacycle rings is chiral. In someembodiments, only one carbon atom in each of the one or two 4-, 5-, 6-,and 7-membered phosphacycle or azacycle rings is chiral. In someembodiments, at least one of the carbon atoms in at least one of the oneor two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings ischiral. In some embodiments, at least one of die carbon atoms in each ofthe one or two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle ringsis chiral. In some embodiments, at least two of the carbon atoms in anyone of the 4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings arechiral. In some embodiments, at least two of the carbon atoms in atleast one of the one or two 4-, 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, at least two of thecarbon atoms in each of the one or two 4-, 5-, 6-, and 7-memberedphosphacycle or azacycle rings are chiral. In some embodiments, exactlytwo of the carbon atoms in at least one of the one or two 4-, 5-, 6-,and 7-membered phosphacycle or azacycle rings are chiral. In someembodiments, exactly two of the carbon atoms in each of the one or two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least three of the carbon atoms in any one of the4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least three of the carbon atoms in at least one ofthe one or two 4-, 5-, 6-, and 7-membered phosphacycle or azacycle ringsare chiral. In some embodiments, at least three of the carbon atoms ineach of the one or two 4-, 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, exactly three of thecarbon atoms in at least one of the one or two 4-, 5-, 6-, and7-membered phosphacycle or azacycle rings are chiral. In someembodiments, exactly three of the carbon atoms in each of the one or two4-, 5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least four of the carbon atoms in any one of the5-, 6-, and 7-membered phosphacycle or azacycle rings are chiral. Insome embodiments, at least four of the carbon atoms in at least one ofdie one or two 5-, 6-, and 7-membered phosphacycle or azacycle rings arechiral. In some embodiments, at least four of the carbon atoms in eachof the one or two 5-, 6-, and 7-membered phosphacycle or azacycle ringsare chiral. In some embodiments, exactly four of the carbon atoms 111 atleast one of the one or two 5-, 6-, and 7-membered phosphacycle orazacycle rings are chiral. In some embodiments, exactly four of thecarbon atoms in each of the one or two 5-, 6-, and 7-memberedphosphacycle or azacycle rings are chiral. The ligatingcompound-chromium complex may or may not be optically active.

Preferably, when the ligating compound-chromium complex contains onlyone 4-, 5-, 6-, and 7-membered phosphacycle ring and no azacycle ringattached to [L(R₅)_(q)]r, one, preferably two, L atoms in thephosphacycle ring attached to the P atom in the phosphacycle ring whichis attached to [L(R₅)_(q)]_(p) are carbon, and one, more preferably two,of these L atoms are chiral. Preferably, when the ligatingcompound-chromium complex contains two 4-, 5-, 6-, and 7-memberedphosphacycle or azacycle rings attached to [L(R₅)_(q)]_(p), one to fourL atoms in the phosphacycle or azacycle rings attached to the P or Natoms in the phosphacycle or azacycle rings which are attached to[L(R₅)_(q)]_(p) are carbon atoms, and one, preferably two, morepreferably three, most preferably four of these L atoms are chiral.

In some embodiments, none of the 4-, 5-, 6-, and 7-membered phosphacycleor azacycle rings of the invention is chiral, preferably one or more4-membered rings have chiral carbon atoms at the 2- and 4-positions,preferably both chiral carbon atoms have the R configuration or bothhave the S configuration; one or more 5-membered rings have chiralcarbon atoms at the 2- and 5-positions, preferably both chiral carbonatoms have the R configuration or both have the S configuration; one ormore 6-membered rings have chiral carbon atoms at the 2- and6-positions, preferably both chiral carbon atoms have the Rconfiguration or both have the S configuration; and one or more7-membered rings have chiral carbon atoms at the 2- and 7-positions,preferably both chiral carbon atoms have the R configuration or bothhave the S configuration. Preferably one, more preferably two, 4-, 5-,6-, and 7-membered phosphacycle or azacycle rings have exactly twochiral carbon atoms in each ring.

The ligating compound-chromium complexes may comprise a single isomer ormixture of various isomers, including stereoisomers, whetherconfigurational, conformational, geometric, or optical. Mixtures ofligating compound-chromium complexes comprising chiral ligatingcompound-chromium complexes which are racemic, enantioenriched, orenantiomerically pure are preferred.

The ligating compound-chromium complexes having only one 4-, 5-, 6-, and7-membered phosphacycle ring and no azacycle ring, and wherein thephosphacycle ring has two chiral carbons, may have the followingconfigurational isomers: R,R; R,S; S,R; and S,S. In an embodiment of theinvention, the ligating compound-chromium complex is a mixture ofligating compound-chromium complexes substantially comprising the R,Sand S,R isomers of a single ligating compound-chromium complex in anyproportion, more preferably the ligating compound-chromium complex is amixture of ligating compound-chromium complexes substantially comprisingthe R,R and S,S isomers of a single ligating compound-chromium complexin any proportion.

When the ligating compound-chromium complex contains a ligating compoundhaving one 4-, 5-, 6-, or 7-membered phosphacycle ring and oneadditional 4-, 5-, 6-, or 7-membered phosphacycle or azacycle ringwherein each ring has two chiral carbons, the ligating compound-chromiumcomplex may have the following configurational isomers: R,R,R,R;R,R,R,S; R,R,S,R; R,S,R,R; S,R,R,R; R,R,S,S; R,S,R,S; S,R,R,S; R,S,S,R;S,R,S,R; S,S,R,R; R,S,S,S; S,R,S,S; S,S,R,S; S,S,S,R; and S,S,S,S; theconfigurational isomers of the ligating compound-chromium complex are acombination of the configurational isomers of the two phosphacycle andazacycle rings, each having the configurational choices of R,R; R,S;S,R; and S,S; each of the foregoing is an embodiment of the invention.Preferably both phosphacycle or azacycle rings of the ligatingcompound-chromium complex have the same configuration, for example, bothare R,R or R,S or S,R or S,S, whereby preferred isomer configurations ofthe ligating compound-chromium complex are R,R,R,R; R,S,R,S; S,R,S,R;and S,S,S,S.

In a preferred embodiment of the invention, the ligatingcompound-chromium, complex is a mixture substantially comprising theR,S,R,S and S,R,S,R isomers of a single ligating compound-chromiumcomplex in any proportion, more preferably the ligatingcompound-chromium complex is a mixture substantially comprising theR,R,R,R and S,S,S,S isomers of a single ligating compound-chromiumcomplex in any proportion.

Preferably [L(R₅)_(q)] of the phosphacycle or azacycle independentlyselected is C(R₅), N, N(R₅), or C(R₅)₂; X₁ is phosphorus or nitrogen; tand v are each independently 1, 2, 3, or 4. Preferably one to six[L(R₅)_(q)] groups of each 4-, 5-, 6-, and 7-membered phosphacycle orazacycle are C(R₅) or C(R₅)₂, more preferably C(R₅)₂. Preferably atleast one, more preferably two, even more preferably three, still morepreferably four, [L(R₅)_(q)] groups of each phosphacycle or azacycle areC(R₅)₂. Preferably at least one, more preferably two, [L(R₅)_(q)] groupsof each phosphacycle or azacycle are C(R₅). Preferably one, morepreferably two, of the C(R₅) or C(R₅)₂ groups of at least onephosphacycle or azacycle are attached to a P or N atom in thephosphacyclc or azacycle which is attached to [L(R₅)_(q)]_(p).Preferably both R₅ groups of the one, more preferably two, C(R₅)₂ groupsattached to a P or N atom in at least one phosphacycle or azacycle whichis attached to [L(R₅)_(q)]_(p) are identical; more preferably they arenot identical. Preferably exactly one R₅ group of at least one,preferably two, C(R₅) or C(R₅)₂ groups attached to a P or N atom in atleast one phosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p)is hydrogen, more preferably exactly one R₅ group of at least one,preferably two, C(R₅) or C(R₅)₂ groups attached to a P or N atom in atleast one phosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p)is not hydrogen. Preferably both C(R₅) or C(R₅)₂ groups attached to a Por N atom in at least one phosphacycle or azacycle which is attached to[L(R₅)_(q)]_(p) are identical to each other. More preferably twoC(R₅)_(q) groups are attached to a P or N atom in each phosphacycle orazacycle which is attached to [L(R₅)_(q)]_(p). More preferably all[L(R₅)_(q)] groups of the phosphacycles or azacycle which are directlyattached to the P or N atom in each phosphacycle or azacycle areindependently C(R₅)_(q) as represented by:

and their enantiomers wherein C(R₅)_(q) is C(R₅), C(R₅)₂, or C(R₅)H,preferably C(R₅)H; X₁ is phosphorus or nitrogen; preferably the R₅groups of the C(R₅)H groups attached to the P or N atom in eachphosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p) are nothydrogen, and wherein, as mentioned above, both the R-configuration anddie S-configuration are meant for C(R₅)H; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; two or moreR₃, R₄ or R₅ groups are optionally linked together to form cyclicstructures containing from 4 to 10 ring atoms, preferably from 4 to 7ring atoms; two or more R₅ groups independently are linked together withat least one L atom to form a cyclic structure that contains from 3 to10 ring atoms, preferably from 3 to 7 ring atoms; two R₅ groups attachedto the same L atom may be optionally linked together to form a cyclicstructure that contains from 3 to 10 ring atoms, preferably from 3 to 7ring atoms; optionally from two to ten, preferably from two to six,independently selected ligating compound-chromium complexes may belinked together via their respective independently selected R₃, R₁ or R₅groups to form a poly(ligating compound-chromium complex) species.Preferably both C(R₅)H groups attached to the P or N atom in diephosphacycle or azacycle which is attached to [L(R₅)_(q)]_(p) are thesame. Preferably both C(R₅)H groups attached to the P atom in thephosphacycle which is attached to [L(R₅)_(q)]_(p) have the same R or Sconfiguration. Preferably when X₁ is a P atom and X₁, R₃, and R₄ form aphosphacycle, the phosphacycle is identical to the phosphacycle formedby P, R₁ and R₂. Preferably die L atoms of phosphacycles or azacyclesare independently carbon or nitrogen. Preferably at least two L atoms ineach phosphacycle or azacycle are carbon. Preferably t and v are eachindependently 1, 2, or 3, preferably 1 or 2. Preferably at least one oft and v is 2, more preferably t is 2. In a preferred embodiment, t is 2;and at least one, preferably two, of L in the phosphacycle is carbon. Ina preferred embodiment, t is 2; and at least one, preferably two, of Lin the phosphacycle is nitrogen. In a preferred embodiment, v is 2; andat least one, preferably two, of L in the ring comprising X₁ are carbon.In a preferred embodiment, v is 2; and at least one, preferably two, ofL in the ring comprising X₁ are nitrogen. More preferably X₁ isphosphorus. More preferably t and v are each 2. More preferably t and vare each 2 and X₁ is phosphorus. In a preferred embodiment, the X₁, R₃,and R₄ groups of X₁R₃(R₅)_(m) do not form a cycle, m is 0 or 1,preferably m is 1; preferably X₁ is nitrogen, more preferably X₁ isphosphorus. In preferred phosphacycle-containing ligatingcompound-chromium complexes X₁ is phosphorus and 5-membered ligatingcompound-chromium complexes are represented by:

wherein q is 1 or 2; preferably L(R₅)_(q) of the phosphacycles is C(R₅),N(R₅), or C(R₅)₂, preferably [L(R₅)_(q)]_(p) is C(R₅), N(R₅), C(R₅)₂,C(R₅)C(R₅) or C(R₅)₂C(R₅)₂, more preferably N(R₅) or C(R₅)C(R₅); theC(R₅)_(q) attached to P is C(R₅), C(R₅)₂, or C(R₅)H, preferably C(R₅)H;further provided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species. Preferably at leastone, more preferably two, phosphacycles contain at least one, preferablytwo, [L(R₅)_(q)] groups each which are C(R₅) or C(R₅)₂. At most one bondin at least one phosphacycle is an unsaturated bond, preferably allbonds in at least one phosphacycle are saturated bonds. Preferably atleast one, preferably two, 5-membered phosphacycles are saturated,meaning they contain no unsaturated bonds. Preferably one 5-memberedphosphacycle is saturated, and one phosphacycle, preferably one5-membered phosphacycle, has two unsaturated bonds, preferably exactlyone unsaturated bond. Preferably one 5-membered phosphacycle has exactlyone unsaturated bond, and one phosphacycle, preferably one 5-memberedphosphacyclc, has two unsaturated bonds, preferably exactly oneunsaturated bond, more preferably no unsaturated bonds. Preferably theunsaturated bonds are carbon-carbon unsaturated bonds. Preferably theunsaturated bonds are carbon-nitrogen unsaturated bonds.

Preferred 5-membered phosphacycles of the phosphacycle-containingligating compound-chromium complex are independently selected, asrepresented by:

and their enantiomers.

Preferred 5-membered ring phosphacycle-containing ligatingcompound-chromium complexes may be built up by independently selectingone preferred 5-membered phosphacycle from above, connecting it to onevalence of the [L(R₅)_(q)]_(p) divalent linking group, and connectingthe remaining free valence of the divalent linking group either to asecond independently selected phosphacycle, preferably a preferred5-membered phosphacycle from above, or to X₁R₃R₄, wherein X₁ isphosphorus or nitrogen, preferably phosphorus, to form a ligatingcompound and then combining the ligating compound with a source ofchromium to introduce the [Cr] group.

Non-limiting examples of preferred non-5-membered ringphosphacycle-containing ligating compound-chromium complexes arerepresented by:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species. Preferably the[L(R₅)_(q)]_(p) divalent linking group is NR₅, C(R₅), C(R₅)C(R₅), C(R₅)₂or C(R₅)₂C(R₅)₂, preferably N(R₅).

Non-limiting examples of the preferred 5-membered ringphosphacycle-containing ligating compound-chromium complexes arerepresented by

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to die same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species. Preferably the[L(R₅)_(q)]_(p) divalent linking group is NR₅, C(R₅), C(R₅)C(R₅), C(R₅)₂or C(R₅)₂C(R₅)₂; preferably N(R₅).

Preferably exactly one R₅ group in at least one, preferably two. C(R₅)or C(R₅)₂ groups attached to the P atom in at least one, preferably two,phosphacycles is hydrogen. Representative, but not limiting, examplesare:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species.

Preferably any R₅ groups attached to the nitrogen atoms in the5-membered phosphacycles are not hydrogen, preferably any R₅ groupsattached to the nitrogen atoms in the 5-membered phosphacycles arehydrocarbyl, preferably C₁₋₄ alkyl, C₆₋₁₀ aryl, or C₇₋₁₀ arylalkyl, morepreferably methyl, ethyl, phenyl, benzyl, or tolyl; preferably the R₅groups attached to the ring carbon atom of the C(R₅) or C(R₃)₂ groups atthe 3- and 4-positions on the 5-membered phosphacycle are hydrogenatoms; preferably the R₅ groups attached to at least one of the ringcarbon atoms of the C(R₅) groups, wherein the ring carbon atoms of theC(R₅) groups are bonded to another ring atom by means of an unsaturatedbond, preferably carbon-carbon unsaturated bond, are hydrogen atoms orare part of an aromatic ring which is fused to the phosphacycle.

Representative, but not limiting, examples are:

and their enantiomers.

Preferably at least one, preferably two, of the R; groups attached tothe ring carbon atom of die C(R₅) or C(R₅)₂ groups at the 2- and5-positions on die 5-membered phosphacycle are independently alkyl,substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl, or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, preferably arylor substituted aryl; preferably exactly one R₅ group attached to thering carbon atom of the C(R₅) or C(R₅)₂ group at each 2-position and ateach 5-position on the 5-membered phosphacycle is alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroaryl, or substituted heteroaryl, preferably aryl, substitutedaryl, heteroaryl, or substituted heteroaryl, more preferably aryl orsubstituted aryl; preferably exactly one R₅ group attached to the ringcarbon atom of any C(R₅)₂ groups at each 2-position and at each5-position on the 5-membered phosphacycle is independently hydrogen,methyl, ethyl, propyl, butyl, or pentyl, preferably hydrogen or methyl,more preferably hydrogen; preferably R₃ and R₄ are independently alkyl,substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl, or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, more preferablyaryl or substituted aryl; preferably exactly one R₅ group attached tothe ring carbon atom of the C(R₅) or C(R₅)₂ group at each 2-position andat each 5-position on the 5-membered phosphacycle is independently arylor substituted aryl, exactly one R₅ group attached to the ring carbonatom of any C(R₅)₂ groups at each 2-position and at each 5-position onthe 5-membered phosphacycle is a hydrogen, and R₃ and R₄ areindependently alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heteroaryl, or substituted heteroaryl, preferably aryl,substituted aryl, heteroaryl, or substituted heteroaryl, more preferablyaryl or substituted aryl. Preferably the aryl, substituted aryl,heteroaryl, or substituted heteroaryl groups at the 2-position and the5-position on the 5-membered phosphacycle are identical. Preferably R₃,R₄, and R₅ are each independently C₁₋₄₀ substituted or unsubstitutedalkyl, preferably C₁₋₂₀ substituted or unsubstituted alkyl, morepreferably C₁₋₁₂ substituted or unsubstituted alkyl; C₂₋₄₀ substitutedor unsubstituted aryl, preferably C₂₋₂₀ substituted or unsubstitutedaryl, more preferably C₂₋₃₂ substituted or unsubstituted aryl; C₂₋₄₀substituted or unsubstituted arylalkyl, preferably C₂₋₂₀ substituted orunsubstituted arylalkyl, more preferably C₂₋₁₂ substituted orunsubstituted arylalkyl; C₂₋₄₀ substituted or unsubstituted heteroaryl,preferably C₂₋₂₀ substituted or unsubstituted heteroaryl, morepreferably C₂₋₁₂ substituted or unsubstituted heteroaryl; preferably R₅independently is C₁₋₄ alkyl, C₆₋₁₀ aryl, or C₇₋₁₀ arylalkyl when R₅ isattached to a ring nitrogen atom of the 5-membered ring phosphacycle;further provided that in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more R₃, R₄ or R₅ groups areoptionally linked together to form cyclic structures containing from 4to 10 ring atoms, preferably from 4 to 7 ring atoms; two or more R₅groups independently are linked together with at least one L atom toform a cyclic structure that contains from 3 to 10 ring atoms,preferably from 3 to 7 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms, preferably from 3 to 7 ring atoms;optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound-chromium complex) species.

In a preferred embodiment, R₃, R₄, and R₅ attached to a ring nitrogenatom of the 5-membered ring phosphacycle are Ar, R₅ attached to a ringnitrogen atom of the 5-membered ring phosphacycle is Ar′, wherein Arindependently is C₂₋₄₀ substituted or unsubstituted aryl, preferablyC₂₋₂₀ substituted or unsubstituted aryl, more preferably C₂₋₁₂substituted or unsubstituted aryl; C₂₋₄₀ substituted or unsubstitutedarylalkyl, preferably C₂₋₂₀ substituted or unsubstituted arylalkyl, morepreferably C₂₋₁₂ substituted or unsubstituted arylalkyl; C₂₋₄₀substituted or unsubstituted heteroaryl, preferably C₂₋₂₀ substituted orunsubstituted heteroaryl, more preferably C₂₋₁₂ substituted orunsubstituted heteroaryl, and Ar′ independently is C₁₋₄ alkyl, C₆₋₁₀aryl, or C₇₋₁₀ arylalkyl.

In preferred ligating compound-chromium complexes L of die phosphacyclesis carbon and 5-membered ligating compound-chromium complexes arerepresented by:

wherein q is 1 or 2; preferably [L(R₅)_(q)]_(p) is C(R₅), N(R₅), C(R₅)₂,C(R₅)C(R₅) or C(R₅)₂C(R₅)₂, more preferably N(R₅) or C(R₅)C(R₅); theC(R₅)_(q) attached to P is C(R₅), C(R₅)₂, or C(R₅)H, preferably C(R₅)H.

In preferred ligating compound-chromium complexes, [L(R₅)_(q)]_(p) ofthe divalent linking group is NR₅ and 5-membered phosphacycle-containingligating compound-chromium complexes are represented by:

wherein q is 1 or 2; the C(R₅)_(q) attached to P is C(R₅), C(R₅)₂, orC(R₅)H, preferably C(R₅)H.

In preferred ligating compound-chromium complexes, [L(R₅)_(q)] at the 3-and 4-positions of the phosphacycle ring are CH₂; [L(R₅)_(q)] at the 2-and 5-positions of the phosphacycle ring are CR₅H; [L(R₅)_(q)]_(p) ofthe divalent linking group is NR₅, and 5-memberedphosphacycle-containing ligating compound-chromium complexes arerepresented by:

In preferred ligating compound-chromium complexes, [L(R₅)_(q)] at the 2-and 5-positions of the phosphacycle ring are CR₅H; the carbon atoms atthe 2- and 5-positions are chiral; preferably both carbon atoms at the2- and 5-positions in each phosphacycle ring have the same R or Sconfiguration; [L(R₅)_(q)]_(p) of the divalent linking group is NR₅;preferably [L(R₅)_(q)] at the 3- and 4-positions of the phosphacyclering are CH₂, and 5-membered phosphacycle-containing ligatingcompound-chromium complexes are represented by:

and their enantiomers.

Non-limiting examples of the phosphacycle-containing ligatingcompound-chromium complexes are:

and their enantiomers.

In preferred phosphacycle-containing ligating compound chromiumcomplexes, Ar at the 2- and 5-positions of the phosphacycle rings isphenyl optionally substituted with R₅; [L(R₅)_(q)]_(p) of the divalentlinking group is NR₅; preferably [L(R₅)_(q)] at the 3- and 4-positionsof the phosphacycle ring are CH₂, and 5-membered phosphacycle-containingligating compound chromium complexes are represented by:

and their enantiomers wherein n independently selected is an integerfrom zero to five, preferably from zero to three.

Preferably Ar independently is C₂₋₄₀ substituted or unsubstituted aryl,preferably C₂₋₂₀ substituted or unsubstituted aryl, more preferablyC₂₋₁₂ substituted or unsubstituted aryl; C₂₋₄₀ substituted orunsubstituted heteroaryl, preferably C₂₋₂₀ substituted or unsubstitutedheteroaryl, more preferably C₂₋₁₂ substituted or unsubstitutedheteroaryl; preferably Ar is independently phenyl, substituted phenyl,furanyl, substituted furanyl, thienyl, substituted thienyl, pyrrolyl,substituted pyrrolyl, pyridinyl, and substituted pyridinyl, morepreferably phenyl, substituted phenyl, and furanyl; further providedthat in at least one phosphacycle of the phosphacycle-containingligating compound, both atoms directly bonded to P or X₁ are sp³hybridized; two or more Ar, Ar′ or R₅ groups are optionally linkedtogether to form cyclic structures containing from 4 to 10 ring atoms,preferably from 4 to 7 ring atoms; two or more R₅ groups independentlyare linked together with at least one L atom to form a cyclic structurethat, contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; two R₅ groups attached to the same L atom may be optionallylinked together to form a cyclic structure that contains from 3 to 10ring atoms, preferably from 3 to 7 ring atoms; optionally from two toten, preferably from two to six, independently selected ligatingcompound-chromium complexes may be linked together via their respectiveindependently selected Ar, Ar′ or R₅ groups to form a poly(ligatingcompound-chromium complex) species. When PR₃R₄ is non-cyclic (i.e., itdoes not form a phosphacycle), the atom of each R₃ or R₄ group directlyattached to the phosphorus-atom is considered to be at the 1-position ofthat particular group for the purpose of numbering the positions ofatoms or substituents in the R₃ or R₄ group. In a preferred embodimentof die ligating compound-chromium complexes wherein die PR₃R₄ group isnon-cyclic, R₃ and R₄ independently are represented by alkyl,substituted alkyl, phenyl, substituted phenyl, furanyl, substitutedfuranyl, thienyl, substituted thienyl, pyrrolyl, substituted pyrrolyl,pyridinyl, and substituted pyridinyl; preferably thephosphacycle-containing ligating compound chromium complexes arerepresented by

and their enantiomers wherein Ar independently is halogen; C₁₋₄₀substituted or unsubstituted alkyl, preferably C₁₋₂₀ substituted orunsubstituted alkyl, more preferably C₁₋₁₂ substituted or unsubstitutedalkyl, even more preferably C₁₋₆ substituted or unsubstituted alkyl,especially methyl, trifluoromethyl, methoxy, ethyl, ethoxy, propyl,isopropyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, hexyl; C₂₋₄₀substituted or unsubstituted aryl, preferably C₂₋₂₀ substituted orunsubstituted aryl, more preferably C₂₋₁₂ substituted or unsubstitutedaryl, especially phenyl, fluorophenyl, difluorophenyl, trifluorophenyl,tolyl, dimethylphenyl, t-butylphenyl, di-t-butylphenyl, methoxyphenyl,ethoxyphenyl, di-t-butylmethoxyphenyl, cyanophenyl, nitrophenyl; C₂₋₄₀substituted or unsubstituted heteroaryl, preferably C₂₋₂₀ substituted orunsubstituted heteroaryl, more preferably C₂₋₁₂ substituted orunsubstituted heteroaryl, especially substituted or unsubstitutedpyridyl, thienyl, furanyl, pyrrolyl; X″ independently is hydrogen;halogen, preferably fluorine, chlorine or bromine, more preferablyfluorine or chlorine, even more preferably fluorine; C₁₋₄₀ substitutedor unsubstituted alkyl, preferably C₁₋₂₀ substituted or unsubstitutedalkyl, more preferably C₁₋₁₂ substituted or unsubstituted alkyl, evenmore preferably C₁₋₆ substituted or unsubstituted alkyl, especiallymethyl, trifluoromethyl, methoxy, ethyl, ethoxy, propyl, isopropyl,n-butyl, i-butyl, s-butyl, t-butyl, pentyl, hexyl; C₂₋₄₀ substituted orunsubstituted aryl, preferably C₂₋₂₀ substituted or unsubstituted aryl,more preferably C₂₋₁₂ substituted or unsubstituted aryl, especiallyphenyl, fluorophenyl, difluorophenyl, trifluorophenyl, tolyl,dimethylphenyl; C₂₋₄₀ substituted or unsubstituted arylalkyl, preferablyC₂₋₂₀ substituted or unsubstituted arylalkyl, more preferably C₂₋₁₂substituted or unsubstituted arylalkyl, especially benzyl, phenethyl,and methylbenzyl; nitro or cyano; further provided that in at least onephosphacycle of the phosphacycle-containing ligating compound, bothatoms directly bonded to P or X₁ are sp³ hybridized; two or more Ar, X″or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms, preferably from 4 to 7 ring atoms;two or more R₅ groups independently are linked together with at leastone L atom to form a cyclic structure that contains from 3 to 10 ringatoms, preferably from 3 to 7 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms, preferably from 3 to 7 ringatoms; optionally from two to ten, preferably from two to six,independently selected ligating compound-chromium complexes may belinked together via their respective independently selected Ar, X″ or R₅groups to form a poly(ligating compound-chromium complex) species. X′″is independently N, O or S, preferably O. Preferably X″ independently ishydrogen, fluorine, chlorine, methyl, methoxy, t-butyl, phenyl, nitro orcyano. Preferably R₃ and R₄ independently are substituted orunsubstituted phenyl or unsubstituted furanyl. Preferably R₃ or R₄independently is substituted phenyl, and at least one X″ on at leastone, preferably each, substituted phenyl is halogen, preferably fluorineor chlorine, C₁₋₄ alkyl or substituted alkyl, preferably methyl,trifluoromethyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy,C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, more preferablyfluorine, chlorine or methyl, even more preferably fluorine; preferablyat least one, more preferably each, substituted phenyl is substituted atthe 2-position with cyano, nitro, fluorine, chlorine, bromine or iodine,preferably fluorine or chlorine, more preferably fluorine and issubstituted at one or more of the 3-, 4-, 5-, 6-positions with cyano,nitro, fluorine, chlorine, bromine or iodine, preferably fluorine orchlorine, more preferably fluorine; preferably at least one, morepreferably each, substituted phenyl is independently substituted at the2-position and the 4-position with cyano, nitro, fluorine, chlorine,bromine or iodine, preferably fluorine or chlorine, more preferablyfluorine; preferably at least one, more preferably each, substitutedphenyl is substituted at the 2-position with cyano, nitro, fluorine,chlorine, bromine or iodine, preferably fluorine or chlorine, morepreferably fluorine; preferably at least one, more preferably each,substituted phenyl is substituted at the 6-position with hydrogen,fluorine or chlorine, preferably hydrogen or fluorine, more preferablyhydrogen; preferably at least one, more preferably each, substitutedphenyl is substituted at the 2-position with fluorine, at the 4-positionwith hydrogen or fluorine, and at the 6-position with hydrogen.Preferably R₃ and R₄ independently are substituted or unsubstitutedpyridinyl. Preferably R₃ or R₄ independently is substituted pyridinyl,and at least one X″ on at least one, preferably each, substitutedpyridinyl is halogen, preferably fluorine or chlorine, C₁₋₄ alkyl,preferably methyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy,C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, more preferablyfluorine, chlorine or methyl, even more preferably fluorine; preferablyat least one, more preferably each, substituted pyridinyl is substitutedat the 2-position with cyano, nitro, fluorine, chlorine, bromine oriodine, preferably fluorine or chlorine, more preferably fluorine.Preferably R₃ and R₄ independently are substituted or unsubstitutedpyridinyl. Preferably R₃ or R₄ independently is substituted pyridinyl,and at least one X″ on at least one, preferably each, substitutedpyridinyl is halogen, preferably fluorine or chlorine, C₁₋₄ alkyl,preferably methyl or t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy,C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano or nitro, more preferablyfluorine, chlorine or methyl, even more preferably fluorine. PreferablyR₃ and R₄ independently are substituted or unsubstituted pyrrolyl.Preferably R₃ or R₄ independently is substituted pyrrolyl, and at leastone X″ on at least one, preferably each, substituted pyrrolyl ishalogen, preferably fluorine or chlorine, C₁₋₄ alkyl, preferably methylor t-butyl, C₁₋₄ alkoxy, preferably methoxy or ethoxy, C₆₋₁₀ aryl,preferably phenyl or tolyl, cyano or nitro, more preferably fluorine,chlorine or methyl, even more preferably methyl. Preferably R₃ and R₄independently are substituted or unsubstituted furanyl. Preferably R₃ orR₄ independently is substituted furanyl, and at least one X″ on at leastone, preferably each, substituted furanyl is halogen, preferablyfluorine or chlorine, C₁₋₄ alkyl, preferably methyl or t-butyl, C₁₋₄alkoxy, preferably methoxy or ethoxy, C₆₋₁₀ aryl, preferably phenyl ortolyl, cyano or nitro, more preferably fluorine, chlorine or methyl,even more preferably methyl. Preferably R₃ and R₄ independently aresubstituted or unsubstituted thienyl. Preferably R₃ or R₄ independentlyis substituted thienyl, and at least one X″ on at least one, preferablyeach, substituted thienyl is halogen, preferably fluorine or chlorine,C₁₋₄ alkyl, preferably methyl or t-butyl, C₁₋₄ alkoxy, preferablymethoxy or ethoxy, C₆₋₁₀ aryl, preferably phenyl or tolyl, cyano ornitro, more preferably fluorine, chlorine or methyl, even morepreferably methyl.

Non-limiting examples of the phosphacycle-containing ligating compoundchromium complexes are:

and their enantiomers wherein in at least one phosphacycle of thephosphacycle-containing ligating compound, both atoms directly bonded toP or X₁ are sp³ hybridized; two or more Ar or R₅ groups are optionallylinked together to form cyclic structures containing from 4 to 10 ringatoms, preferably from 4 to 7 ring atoms; two or more R₅ groupsindependently are linked together with at least one L atom to form acyclic structure that contains from 3 to 10 ling atoms, preferably from3 to 7 ring atoms; two R₅ groups attached to the same L atom may beoptionally linked together to form a cyclic structure that contains from3 to 10 ring atoms, preferably from 3 to 7 ring atoms; optionally fromtwo to ten, preferably from two to six, independently selected ligatingcompound-chromium complexes may be linked together via their respectiveindependently selected Ar or R₅ groups to form a poly(ligatingcompound-chromium complex) species.

In preferred ligating compound-chromium complexes, Ar at the 2- and5-positions of the phosphacycle rings is phenyl optionally substitutedwith R₅; [L(R₅)_(q)]_(p) of the divalent linking group is NR₅, and5-membered phosphacycle-containing ligating compound chromium complexesare represented by:

and their enantiomers, wherein n independently selected is an integerfrom zero to five, preferably from zero to three, more preferably zeroto one; R₅ is halogen, C₁₋₄₀ substituted or unsubstituted alkyl, C₁₋₄₀substituted or unsubstituted aryl; preferably fluorine, chlorine,bromine, C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₂₀ substituted orunsubstituted aryl; more preferably fluorine, chlorine, C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; R₃ is C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₄₀ substitutedor unsubstituted aryl; preferably C₁₋₂₀ substituted or unsubstitutedalkyl, C₁₋₂₀ substituted or unsubstituted aryl; more preferably C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; X″ is hydrogen, halogen, C₁₋₄ alkyl or substituted alkyl, C₆₋₁₀aryl or substituted aryl, cyano or nitro, preferably hydrogen, fluorine,chlorine, bromine, methyl, ethyl, propyl, butyl, phenyl, tolyl, xylyl,methoxy, ethoxy, propoxy, trifluoromethyl or t-butyl, cyano, morepreferably hydrogen, fluorine, chlorine, methyl, ethyl, propyl, butyl,phenyl, tolyl, methoxy, ethoxy, propoxy, trifluoromethyl, cyano, evenmore preferably hydrogen, fluorine, methyl, or methoxy.

In preferred ligating compound-chromium complexes, X″ at the 2-positionof the phenyl ring attached to P is fluorine, X″ at the 6-position ofthe phenyl ring attached to P is hydrogen, and 5-memberedphosphacycle-containing ligating compound chromium complexes arerepresented by:

and their enantiomers, wherein n independently selected is an integerfrom zero to five, preferably from zero to three, more preferably zeroto one; R₅ is halogen, C₁₋₄₀ substituted or unsubstituted alkyl, C₁₋₄₀substituted or unsubstituted aryl; preferably fluorine, chlorine,bromine, C₁₋₂₀ substituted or unsubstituted alkyl, C₁₋₂₀ substituted orunsubstituted aryl; more preferably fluorine, chlorine, C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₀ substituted or unsubstitutedaryl; R₃ is C₁₋₄₀ substituted or unsubstituted alkyl, C₁₋₂₀ substitutedor unsubstituted aryl; preferably C₁₋₂₀ substituted or unsubstitutedalkyl, C₁₋₁₂ substituted or unsubstituted aryl; more preferably C₁₋₁₂substituted or unsubstituted alkyl, C₁₋₁₂ substituted or unsubstitutedaryl; X″ is hydrogen, halogen, C₁₋₄ alkyl or substituted alkyl, C₆₋₁₀aryl or substituted aryl, cyano or nitro, preferably hydrogen, fluorine,chlorine, bromine, methyl, ethyl, propyl, butyl, phenyl, tolyl, xylyl,methoxy, ethoxy, propoxy, trifluoromethyl or t-butyl, cyano, morepreferably hydrogen, fluorine, chlorine, methyl, ethyl, propyl, butyl,phenyl, tolyl, methoxy, ethoxy, propoxy, trifluoromethyl, cyano, evenmore preferably hydrogen, fluorine, methyl, or methoxy.

The group Y, which links P and X₁ together in the ligatingcompound-chromium complexes, is a divalent linking group[L(R₅)_(q)]_(p), wherein p is an integer number from 1 to 6, preferablyfrom 1 to 4, preferably 1.2, or 3, more preferably 1 or 2; q is 0, 1, or2; consisting of the linking part [L]_(p) and the R₅ pendant groupswherein the R₅ pendant groups independently selected are attached to theL atoms of die [L]_(p) linking part. The linking part [L]_(p) consistsof 1 to 6, preferably of 1 to 4, preferably 1, 2, or 3, more preferably1 or 2 L atoms; L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur. Preferably L is independently selected from carbon, nitrogen,phosphorus, oxygen, and sulfur. Preferred linking parts [L]_(p), each Lindependently selected, are B, C, N, O, P, S, Si, C—C, C═C, C—N, C═N,C—Si, N—N, C—C—C, C—C═C, C—N—C, C—P—C, C—N═C, C—Si—C, N—C—N, C—N—N,C═N—N, C—N═N, C—O—C, and C—S—C, preferably provided that the linkingpart [L]_(p) is not amidine, N—C═N. In an embodiment of die invention,each L(R₅)_(q) group is independently —N—, —N(R₅)—, —P(R₅)—, —P(O)(R₅)—,—P(S)(R₅)—, —C(O)—, —C(R₅), —C(R₅)₂—, —Si(R₅)₂—, —O—, —S—, S(R₅), and—SO₂—, preferably N, N(R₅), C(R₅), or C(R₅)₂.

In some embodiments, the linking part [L]_(p) consists of C and thedivalent linking group is [C(R₅)_(q)] wherein q is 1 or 2.Representative, but not limiting, [C(R₅)_(q)] linking groups include:

Specific, but not limiting, [C(R₅)_(q)] linking groups include:

In some embodiments, the linking part [L]_(p) is not C and the divalentlinking group is not [C(R₅)_(q)] wherein q is 1 or 2.

In some embodiments, the linking part [L]_(p) consists of C—C and thedivalent linking group is [C(R₅)_(q)]₂ wherein q independently is 1 or 2and at least one q is 2. Representative, but not limiting. [C(R₅)_(q)]₂linking groups include:

Specific, but not limiting, [C(R₅)_(q)]₂ linking groups include:

In some embodiments, the linking part [L]_(p) is not C—C and thedivalent linking group is not [C(R₅)_(q)]₂ wherein q independently is 1or 2 and at least one q is 2.

In some embodiments the linking part [L]_(p) consists of C—C and thedivalent linking group is [C(R₅)]₂ wherein both carbon atoms areconnected with a carbon-carbon unsaturated bond, or both carbon atomsare connected to their respectively R₅ groups with unsaturated bonds.Representative, but not limiting, [C(R₅)₂]₂ linking groups include:

Specific, but not limiting, [C(R₅)]₂ linking groups include:

In some embodiments the linking part [L]_(p) is not C—C and the divalentlinking group is not [C(R₅)]₂ wherein both carbon atoms are connectedwith a carbon-carbon unsaturated bond, or both carbon atoms areconnected to their respectively R₅ groups with unsaturated bonds.

In some embodiments, the linking part [L]_(p) consists of N or N—N andthe divalent linking group is [NR₅] or [NR₅]₂. Representative, but notlimiting, [NR₅] or [NR₅]₂ linking groups include:

Specific, but not limiting, [NR₅] or [NR₅]₂ linking groups include:

In some embodiments, the linking part [L]_(p) is neither N nor N—N andthe divalent linking group is neither [NR₅] nor [NR₅]₂. Preferably [NR₅]does not comprise

It will be appreciated that a diphosphinoimine compound of the formR₁R₂P—P(═NR₅)R₃(R₄) (‘P—P═N’) is a rearranged isomer of thediphosphinoamine compound R₁R₂P—NR₅—PR₃(R₄) (‘P—N—P’) claimed in thepresent invention, as shown by Dyson et al in Inorganica Chimica Acta359 (2006) 2635-2643 and may isomerize to the P—N—P form in the presenceof transition metals, such as chromium in the instant application.

Similarly, it may be possible that a ligating compound of the formR₁R₂P—Y—X₁R₃(R₄)_(m) or R₁R₂P-[L(R₅)_(q)]_(p)—X₁R₃(R₄)_(m) where Y or[L(R₅)_(q)]_(p) is —N(R₅)— and X₁R₃(R₄)_(m) is PR₃R₄, exists in itsisomeric ‘P—P═N’ form. Regardless of the structural formulation of theligating compound in its pure and isolated form, it and its use areembodiments of the present invention, especially if it exists in the‘P—N—P’ form when used in an oligomerization process, more especiallywhen it is bound to chromium in an oligomerization process.

In some embodiments, the linking part [L]_(p) consists of C—N and thedivalent linking group is [C(R₅)_(q)N(R₅)_(q)] wherein q independentlyis 1 or 2 for C(R₅)_(q) and 0 or 1 for N(R₃)_(q). Representative, butnot limiting, [C(R₅)_(q)N(R₅)_(q)] linking groups include:

Specific, but not limiting, [C(R₅)_(q)N(R₅)] linking groups include:

In some embodiments, the linking part [L]_(p) is not C—N and thedivalent linking group is not [C(R₅)_(q)N(R₅)_(q)] wherein qindependently is 1 or 2 for C(R₅)_(q) and 0 or 1 for N(R₅)_(q).Preferably [C(R₅)_(q)N(R₅)_(q)] does not comprise

In some embodiments, the L atoms of the linking part [L]_(p) areselected from the group consisting of B, O, S, Si, and C wherein atleast one L is not C; p is 1, 2, 3, or 4; and the divalent linking groupis [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] wherein X′ independently selectedis BR₅, O, S, SO, SO₂, or Si(R₅)₂; k is 0 or 1; k′ is 0 or 1; r is 1, 2,or 3. Preferably r+k+k′ 1, 2, or 3.

Representative, but not limiting, [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)]linking groups include:

Specific, but not limiting, [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] linkinggroups include:

In some embodiments, die L atoms of the linking part [L]_(p) are notselected from die group consisting of B, O, S, Si, and C wherein atleast one L is not C; p is 1, 2, 3, or 4; and the divalent linking groupis not [(C(R₅)₂)_(k)X′_(r)(C(R₅)₂)_(k′)] wherein X′ independentlyselected is BR₅, O, S, SO, SO₂, or Si(R₅)₂; k is 0 or 1; k′ is 0 or 1; ris 1, 2, or 3.

In preferred phosphacycle-containing ligating compound chromiumcomplexes, represented by:

the L atoms are connected to each other, independently for eachconnection, with single bonds or with unsaturated bonds with the provisothat in at least one phosphacycle of the ligating compound, both atomsdirectly bonded to P or X₁ are sp³ hybridized; preferably at least onephosphacycle does not contain more than one carbon-carbon unsaturatedbond, preferably not more than one unsaturated bond, more preferably atleast one, preferably two, phosphacycles contain no unsaturated bonds;two or more R₃, R₄ or R₅ groups are optionally linked together to formcyclic structures containing from 4 to 10 ring atoms, preferably from 4to 7 ring atoms; two or more R₅ groups independently are linked togetherwith at least one L atom to form a cyclic structure that contains from 3to 10 ring atoms, preferably from 3 to 7 ring atoms; two R₅ groupsattached to the same L atom may be optionally linked together to form acyclic structure that contains from 3 to 10 ring atoms, preferably from3 to 7 ring atoms; optionally from two to ten, preferably from two tosix, independently selected ligating compound-chromium complexes may belinked together via their respective independently selected R₃, R₄ or R₅groups to form a poly(ligating compound-chromium complex) species. In anembodiment of the invention no two R₅, R₃, or R₄ groups are linkedtogether to form a cyclic structure. In an embodiment of the inventionat least two R₅ groups are linked together to form a cyclic structure.Preferably at least one R₅ group on a first L(R₅)_(q) group is linkedtogether with at least one R₅ group on an adjacent second L(R₅)_(q)group together with the L atom from the first L(R₅)_(q) group and the Latom from the adjacent second L(R₅)_(q) group to form an

cyclic structure containing from 4 to 10 atoms, preferably 4 to 7 atoms,in the ring part of the

cyclic structure. Preferably the

ring is a substituted or unsubstituted, saturated or unsaturatedhydrocarbon group, such as cyclopentanediyl, cyclohexanediyl,dioxolanediyl, tetrahydrofurandiyl, pyrrolidinediyl, piperidinediyl,piperazinediyl, pyrazolidinediyl. Preferably the

ring is a substituted or unsubstituted alkenyl or aromatic group, suchas cyclopentenediyl, cyclohexenediyl, cyclopentadienediyl, phenylene,naphthalenediyl, pyridinediyl, pyrrolediyl, imidazoldiyl,pyridazinediyl, pyridazinedionediyl, quinoxalinediyl, thiazolediyl,thiophenediyl, furandiyl, or cyclopentadienyl-diyl, wherein preferablythe cyclopentadienyl group is part of an η⁵-bonded transition metalcomplex, wherein preferably the η⁵-bonded transition metal complexcomprises Fe, Ti, Zr, or Hf.

In preferred ligating compound-chromium complexes of the invention, twoR₅ groups on the same L(R₅)_(q) group, wherein q=2, are linked togetherto form an

cyclic structure containing from 3 to 10 atoms, preferably 3 to 7 atoms,in the ring part of the

cyclic structure. Preferably the

ring is a substituted or unsubstituted, saturated or unsaturatedhydrocarbyl group, such as cyclobutanediyl, cyclopentanediyl,cyclohexanediyl, tetrahydrofurandiyl, or cyclopentenediyl.

In preferred ligating compound-chromium complexes of the invention, atleast one R₅ group on a L(R₅)_(q) group from at least one of the

groups or at least one R₅ group on a

group, wherein the R₃ or R₄ group may be represented as L(R₅)_(q)(R₅),is linked together with at least one R₅ group from the [L(R₅)_(q)]_(p)divalent bridging group between P and X₁ to form an

respectively, cyclic structure containing from 5 to 10 atoms, preferably5 to 7 atoms, in the ring part of the

cyclic structure.

R₃, R₄, and R₅ independently selected are hydrogen, fluoro, chloro,bromo, cyano; substituted or unsubstituted hydrocarbon derivatives,preferably substituted or unsubstituted alkyl groups having 1-20,preferably 1-12, more preferably 1-6, non-hydrogen atoms, preferablymethyl, trifluoromethyl, ethyl, propyl, isopropyl, n-butyl, i-butyl,s-butyl, t-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl; preferablysubstituted or unsubstituted unsaturated groups, including alkylidene,alkenyl, aryl, or arylalkyl groups, having 2-20, preferably 2-12, morepreferably 2-8, still more preferably 2-6, non-hydrogen atoms,preferably vinyl, methylidene, ethylidene, allyl, phenyl,2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,4-dimethylphenyl,2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2-isopropylphenyl,2,6-diisopropylphenyl, 2,6-diisopropyl-4-methylphenyl, 2-fluorophenyl,4-fluorophenyl, 2-trifluoromethylphenyl, naphthyl, anthracenyl,biphenyl, benzyl, naphthylmethyl phenethyl, biphenylmethyl; substitutedor unsubstituted heterohydrocarbon derivatives having 1-20, preferably1-12, more preferably 1-6, non-hydrogen atoms, preferably methoxy,ethoxy, propoxy, isopropoxy, butoxy, phenoxy, methylthio, ethylthio,acetyl, dimethylboryl, diphenylboryl, bis(dimethylamino)boryl,dimethylamino, diethylamino, 2-dimethylaminoethyl, 2-methoxyphenyl,3-methoxyphenyl, 4-methoxyphenyl, 2,6-dimethoxyphenyl,2,6-dimethoxy-4-methylphenyl, 2-di methyl aminophenyl, phenylamino,phenylmethylamino, acetamide, formylamino, benzamido, benzoyl,methylcarboxamide, dimethylcarboxamide, methoxymethyl, ethoxymethyl,phenoxymethyl, methoxyethyl, ethoxyethyl, phenoxyethyl,phospholanylmethyl, diethylphospholanylmethyl, 2-furanyl, 3-furanyl,pyrrolyl, imidazolyl, pyrrolidinyl, piperidinyl, pyridinyl, pyridazinyl,pyrazolidinyl, pyrazinyl, thienyl, thiazolyl, trimethylsilyl,trimethylsilylmethyl, dimethylphenylsilyl, methylsulfinyl,ethylsulfinyl, methylsulfonyl, ethylsulfonyl; or a substituted orunsubstituted heteroatom group having 1-6 non-hydrogen atoms, preferablya nitro group, one oxygen atom, or one sulfur atom, R₃ and R₄ preferablyare substituted or unsubstituted aryl or arylalkyl groups, morepreferably substituted or unsubstituted aryl groups. When two or moreR₃, R₄, or R₅ groups, independently selected, are linked together, themoiety they form is di- or polyvalent, depending on how many R₃, R₄, orR₅ groups are linked together. For example, if two R₃, R₄, or R₅ groupsare linked together, the moiety is divalent; if three R₃, R₁, or R₅groups are linked together, the moiety is trivalent. When two or moreR₃, R₁, or R₅ groups, independently selected, are linked together, thelinked R₃, R₄, or R₅ groups are not hydrogen, fluoro, chloro, bromo orcyano.

In some embodiments, phosphacycle-containing ligating compound chromiumcomplexes of the present invention include the following compositions:

and their enantiomers.

The [Cr]----[Cr] linkage between the two [Cr] groups in the dimer formof the ligating compound-chromium complex is not limited to represent aCr—Cr bond, but rather represents that the two independently selected[Cr] units are connected or associated through bonding interactions, forexample, a Cr—Cr bond; bridging anionic ligands between the chromiumatoms, such as bridging halide ligands, especially chloride, bromide,and iodide; bridging hydride ligands; bridging hydrocarbyl ligands,especially methyl, ethyl, ethanediyl, butanediyl, hexanediyl,octanediyl; bridging carboxylate ligands, especially acetate, octoate,2-ethylhexaneoate; bridging sulfonate ligands, especiallymethanesulfonate, benzenesulfonate, toluenesulfonate,trifluoromethylsulfonate; bridging oxide or sulfide ligands; bridginghydroxide ligands; bridging alkoxide ligands, especially methoxide,ethoxide, propoxide, butoxide; bridging cyanide ligands; or bridgingamido ligands, especially dimethylamido, diethylamide, diisopropylamido;bridging neutral Lewis bases between the chromium atoms, such asbridging carbonyl (CO); bridging phosphines, especiallytrimethylphosphine, triethylphosphine, triphenylphosphine; bridgingethers, especially diethyl ether, tetrahydrofuran; or bridgingthioethers; bridging ligands having multiple anionic and/or neutralsites connecting the chromium atoms, wherein one chromium atom isattached to one site and another chromium atom is attached to anothersite, such as amido-imine ligands, diphosphine ligands, dicarboxylateligands; ionic bonding interactions, such as when a ligatingcompound-chromium complex bearing a positive charge is associated with aligating compound-chromium complex bearing a negative charge. In oneembodiment, the dimer may be formed by connecting two independentlyselected ligating compound-chromium complexes by covalent bondinginteractions between their respective R₁, R₂, R₁, R₄, R₅, or L groups.

The ancillary ligands attached to the chromium atom in [Cr], that is,die ligands attached to the chromium atom, not including the ligatingcompound, can include anionic or neutral ligands. The anionic or neutralligands attached to the chromium atom in [Cr] can arise from the sourceof chromium, from the optional at least one sol vent in which theligating compound and the source of chromium may be contacted to formthe ligating compound-chromium complex, from the ligating compound, fromdie at least one activator, or from other optional components that maybe added. Anionic ligands attached to the chromium atom in [Cr] areselected from the group comprising halide anions, especially chloride,bromide, or iodide; β-ketonates, such as acetylacetonate,hexafluoroacetylacetonate, methylacetylacetonate,3-acetylpentane-2,4-dionate; carboxylate anions, such as formate,acetate, propionate, benzoate, 2-ethylhexanoate, or trifluoroacetate;sulfonates, such as methanesulfonate, benzenesulfonate,p-toluenesulfonate, trifluoromethanesulfonate; hydrocarbyl groups andderivatives thereof, such as methyl, ethyl, propyl, butyl, allyl,neopentyl, phenyl, mesityl, benzyl, or trimethylsilylmethyl; and amideanions, such as dimethylamide, diethylamide, diisopropylamide; alkoxideanions, such as methoxide, ethoxide, or phenoxide; oxide, or sulfide.Neutral ligands attached to the chromium atom in [Cr] are selected fromthe group comprising neutral Lewis bases, including, but not limited toethers, such as THF (tetrahydrofuran) or diethyl ether; alcohols, suchas methanol or ethanol; nitriles, such as acetonitrile or benzonitrile;amines, such as triethylamine or ethylenediamine; phosphines, such astrimethylphosphine, triethylphosphine, triphenylphosphine, orbis(dimethylphosphino)ethane; imines, such as N-ethylidene-benzenamineor N-(1-methylethylidene)-2-propanamine; water; carbonyl (CO);preferably carbonyl and THF.

Optionally from two to ten, preferably from two to six, independentlyselected ligating compound-chromium complexes may be linked together viatheir respective independently selected Ar, Ar′, X″, Y, R₁, R₂, R₃, R₄or R₅ groups to form a poly(ligating compound-chromium complex) species.The poly(ligating compound-chromium complex) species may take the formof dendrimers, oligomers or polymers of the ligating compound-chromiumcomplexes. The poly(ligating compound-chromium complex) species may be alinear, branched, or cyclic dendrimer, oligomer or polymer, wherein eachmonomer unit is an individual independently selected ligatingcompound-chromium complex. In one embodiment all of the individualligating compound-chromium complexes are the same as each other. In oneembodiment the individual ligating compound-chromium complexes are notall the same as each other.

The ligating compound-chromium complexes may be linked to form thepoly(ligating compound-chromium complex) species by removing one or moreindependently selected atoms, preferably one atom, from one or more ofthe respective independently selected Ar, Ar′, X″, R₁, R₂, R₃, R₄ or R₅groups of each ligating compound-chromium complex to provide one or morefree valencies on each ligating compound-chromium complex and thenlinking the ligating compound-chromium complexes having one or more freevalencies to each other at the free valence sites to form thepoly(ligating compound-chromium complex) species. In one embodiment theligating compound-chromium complexes are linked via their correspondingindependently selected Ar, Ar′, X″, Y, R₁, R₂, R₃, R₄ or R₅ groups(e.g., R₁ from one ligating compound-chromium complex is linked with R₁from another ligating compound-chromium complex or Y from one ligatingcompound-chromium complex is linked with Y from another ligatingcompound-chromium complex). In one embodiment the ligatingcompound-chromium complexes are linked, but not via their correspondingindependently selected Ar, Ar′, X″, Y, R₁, R₂, R₃, R₄ or R₅ groups(e.g., R₂ from one Ligating compound-chromium complex is linked with agroup from another ligating compound-chromium complex other than R₂).

In an embodiment, the poly(ligating compound-chromium complex) speciesmay be formed by combining a poly(ligating compound) with a chromiumsource.

In an embodiment, the poly(ligating compound-chromium complex) speciesmay be formed by contacting individual ligating compound-chromiumcomplexes, whereby each individual ligating compound-chromium complexpossesses at least one functional group on at least one Ar, Ar′, X″, Y,R₁, R₂, R₃, R₄ or R₅ group which can combine with a functional group ofanother individual ligating compound-chromium complex to form a bond.

In an embodiment, the poly(ligating compound-chromium complex) speciesmay be formed by linking ligating compound-chromium complexes using theancillary ligands which are part of [Cr], for example, ligatingcompound-chromium complexes which dimerize via bridging chlorideligands. While not wishing to be bound by any particular theory, it isbelieved that a poly(ligating compound-chromium complex) species formedby linking ligating compound-chromium complexes using the ancillaryligands which are part of [Cr] is prone to dissociation underoligomerization conditions, whereas a poly(ligating compound-chromiumcomplex) species in which the individual ligating compound-chromiumcomplexes are linked via their respective Ar, Ar′, X″, Y, R₁, R₂, R₃, R₄or R₅ groups is believed not to dissociate under oligomerizationconditions into its individual ligating compound-chromium complexes.

Specific, but non-limiting, examples of the poly(ligatingcompound-chromium complex) species include:

and their enantiomers.

Preparation of the Ligating Compound-Chromium Complexes

In some embodiments, the invention provides a process to prepare theligating compound-chromium complexes which are useful in theoligomerization of olefins such as ethylene. The ligatingcompound-chromium complex may be prepared by combining in any order a) asource of chromium and b) a phosphacycle-containing ligating compound asdescribed herein, optionally in the presence, of at least one solvent.

The ligating compound-chromium complex formed by combining the source ofchromium and b) a phosphacycle-containing ligating compound optionallymay or may not be isolated; optionally the ligating compound-chromiumcomplex may be formed in situ, for example, in the oligomerizationreactor.

The preparation of the ligating compound-chromium complex may be carriedout at temperatures ranging from −100° C. to 250° C., preferably from−78° C. to 150° C., more preferably from 0° C. to 110° C., even morepreferably from 20° C. to 80° C. The optional at least one solvent inwhich the ligating compound and the source of chromium are contacted toform the ligating compound-chromium complex may be any inert solvent,especially inert solvents selected from the group comprising pentane,hexane, heptane, octane, nonane, decane, cyclohexane, cycloheptane,methylcyclopentane, methylcyclohexane, 1-hexene, 1-octene, benzene,toluene, xylene, ethylbenzene, cumene, mesitylene, commercial saturatedhydrocarbons mixtures, such as Isopar-E™, THF, diethyl ether,chloroform, methylene chloride, dichloroethane, trichloroethane,tetrachloroethane, chlorobenzene, 1,2-dichlorobenzene, chlorobenzene,and 1,2-dichlorobenzene, or mixtures thereof. Preferably the process toprepare the ligating compound-chromium complex is carried out underinert atmosphere conditions. Depending on the reaction conditions, theligating compound-chromium complex may form as a monomer or as a dimer.For example, the reaction of1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene, (Me-DuPhos), withCrCl₃(THF)₃), (trichlorotris(tetrahydrofuran)chromium), in THF gives themonomeric ligating compound-chromium complex Me-DuPhos-CrCl₃(THF), whilein hot toluene the dimeric ligating compound-chromium complex(Me-DuPhos-CrCl₃)₂ forms. In some cases the dimer form of a ligatingcompound-chromium complex may be obtained upon recrystallization of themonomer form.

The source of chromium and the ligating compound may be contacted inproportions to provide Obligating compound ratios from 1000:1 to 1:1000,preferably from 100:1 to 1:100, more preferably from 10:1 to 1:10, evenmore preferably from 1.3:1 to 1:1.3, still even more preferably from1.1:1 to 1:1.1

The terms ‘inert solvent’ and ‘inert atmosphere’ mean that the solvent,respectively, atmosphere, do not interfere substantially with theformation of the ligating compound-chromium complex; preferably thismeans that the solvent, respectively, atmosphere, are substantially freeof oxygen and/or other components which could interfere with formationof the ligating compound-chromium complex or could cause decompositionof the ligating compound or ligating compound-chromium complex.

The preparation of the ligating compound-chromium complex may optionallybe carried out in the presence of an activator. The preparation of theligating compound-chromium complex may occur as part of the process toprepare the catalyst system for the oligomerization of olefins.

It will be appreciated from Dyson et al Inorganica Chimica Acta 359(2006) 2635-2643) that the isomeric ‘P—P═N’ form of diephosphacycle-containing ligating compound R₁R₂P—Y—X₁R₃(R₄)_(m) orR₁R₂P-[L(R₅)_(q)]_(p)—X₁R₃(R₄)_(m), where Y or [L(R₅)_(q)]_(p) is—N(R₅)— and X₁R₃(R₄)_(m) is PR₃R₄, may be used in any method to preparethe ligating compound-chromium complex, including in the methodsdiscussed above, especially if it exists in the ‘P—N—P’ form when usedin an oligomerization process, more especially when it is bound tochromium in an oligomerization process.

Source of Chromium

Sources of chromium, sometimes referred to as “chromium precursors”, areknown in the literature. Illustrative publications include U.S. Pat. No.7,378,537 and U.S. Pat. No. 7,425,661. To the extent permitted by USJaw, these references are incorporated herein.

In one embodiment, die source of chromium is selected from a groupcomprising CrCl₃(THF)₃ (trichlorotris(tetrahydrofuran)chromium),CrBr₃(THF)₃, CrI₃(THF)₃, CrCl₃, CrBr₃, CrI₃, CrCl₂, CrCl₂(THF)₂.Cr(acac)₃, (chromium (III) acetylacetonate), Cr(acetate)₃ (chromium(III) acetate), Cr(2-ethylhexanoate)₃ (chromium (III) 2-ethylhexanoate),(THF)₃CrMeCl₂, (Mes)₃Cr(THF), ((TFA)₂Cr(OEt)₂)₂, (THF)₃CrPh₃,Cr(NMe₃)₂Cl₃, Cr(neopentyl)₃(THF)₃, Cr(CH₂—C₆H₄-o-NMe)₃, Cr(TFA)₃,Cr(CH(SiMe₃)₂)₃, Cr(Mes)₂(THF)₃, Cr(Mes)₂(THF)Cr(Mes)₂(THF)₂,Cr(Mes)Cl(THF)₂, Cr(Mes)Cl(THF)_(0.5), Cr(p-tolyl)Cl₂(THF)₃,Cr(diisopropylamide)₃, Cr(picolinate)₃, CrCl₂(THF)₂, Cr(NO₃)₃,Cr(hexafluoroacetylacetonato)₃, (THF)₃Cr(η²-2,2″biphenyl)Br, Cr(CO)₆,Cr(CO)₃(THF)₃, Cr(CO)₃(NCCH₃)₃, (benzene)Cr(CO)₃, (toluene)Cr(CO)₃ andmixtures thereof. The source of chromium is preferably selected from agroup consisting of CrCl₃(THF)₃, CrCl₃, Cr(acac)₃, Cr(acetate)₃,Cr(2-ethylhexanoate)₃, CrCl₂, CrCl₂(THF)₂, Cr(CO)₆, and mixturesthereof. In die foregoing formulae, “Mes” means mesityl or2,4,6-trimethylphenyl, “TFA” means trifluoroacetate and “acac” meansacetylacetonato.

Catalyst System

In some embodiments, the invention provides an oligomerization catalystsystem for the oligomerization of olefins, wherein die catalyst systemis a composition comprising a) a source of chromium, b) one or moreactivators, and c) at least one, preferably one, phosphacycle-containingligating compound as described herein. Preferably the catalyst system isthe composition comprising one or more activators and at least one,preferably one, phosphacycle-containing ligating compound-chromiumcomplex wherein the at least one, preferably one, ligatingcompound-chromium complex comprises a source of chromium and at leastone, preferably one, phosphacycle-containing ligating compound.

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by combining a) the source ofchromium, b) one or more activators, and c) at least one, preferablyone, phosphacycle-containing ligating compound together in any order,optionally in the presence of at least one solvent, either in thereactor in which the oligomerization process of this invention iscarried out or not in the reactor, either in the presence or absence ofat least one olefin, preferably in the presence of the at least oneolefin, preferably ethylene, to be oligomerized, optionally thephosphacycle-containing ligating compound-chromium complex is formed insitu by combining the phosphacycle-containing ligating compound and thechromium source, optionally the phosphacycle-containing ligatingcompound and the chromium source are combined in situ.

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by a) combining the one or moreactivators with at least one, preferably one, ligating compound and b)combining the resulting combination with the source of chromium.

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by a) combining the one or moreactivators with the source of chromium and b) combining the resultingcombination with at least one, preferably one, ligating compound.

Another embodiment of die catalyst system for the oligomerization ofolefins is the composition prepared by combining the source of chromium,the one or more activators, and at least one, preferably one, ligatingcompound concurrently.

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by a) combining a source of chromiumwith at least one, preferably one, ligating compound and b) notisolating the resulting combination, and c) combining the combinationwith the one or more activators.

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by a) combining a source of chromiumwith at least one, preferably one, ligating compound and b) isolatingthe resulting combination

Another embodiment of the catalyst system for the oligomerization ofolefins is the composition prepared by a) combining a source of chromiumwith at least one, preferably one, ligating compound and b) notisolating the resulting combination.

A more preferred embodiment of die catalyst system for theoligomerization of olefins is the composition prepared by combining a)at least one, preferably one, isolated ligating compound-chromiumcomplex (as described above), which is prepared by combining the sourceof chromium with at least one, preferably one, ligating compound,optionally in the presence of at least one solvent, and isolating theproduct; with b) die one or more activators, optionally in the presenceof one or more solvents.

In some embodiments, the invention provides a process to prepare acatalyst system for the oligomerization of olefins, wherein the catalystsystem is a composition comprising a) a source of chromium, b) one ormore activators, and c) at least one phosphacycle-containing ligatingcompound as described herein. Preferably the catalyst system is thecomposition comprising one or more activators and at least one,preferably one, phosphacycle-containing ligating compound-chromiumcomplex wherein the ligating compound-chromium complex comprises asource of chromium and at least one, preferably one,phosphacycle-containing ligating compound.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, the steps of theprocess comprising combining a) the source of chromium, b) one or moreactivators, and c) at least one phosphacycle-containing ligatingcompound together in any order, optionally in the presence of at leastone solvent, either in the reactor in which the oligomerization processof this invention is carried out or not in the reactor, either in diepresence or absence of at least one olefin, preferably in the presenceof die at least one olefin, preferably ethylene, to be oligomerized.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, the steps of theprocess comprising a) combining the one or more activators with at leastone ligating compound and b) combining the resulting combination withthe source of chromium.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, the steps of theprocess comprising a) combining the one or more activators with thesource of chromium and b) combining the resulting combination with atleast one ligating compound.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, the steps of theprocess comprising combining the source of chromium, the one or moreactivators, and at least one ligating compound concurrently.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, the steps of theprocess comprising a) combining a source of chromium with at least one,preferably one, ligating compound, optionally hi situ, and b) notisolating the resulting combination, and c) combining the combinationwith the one or more activators.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, steps of the processcomprising a) combining a source of chromium with at least one,preferably one, ligating compound, optionally in situ, and b) isolatingthe resulting combination.

Another embodiment of the invention provides a process to prepare acatalyst system for the oligomerization of olefins, steps of the processcomprising a) combining a source of chromium with at least one,preferably one, ligating compound, optionally in situ, and b) notisolating the resulting combination.

A more preferred embodiment of the invention provides a process toprepare a catalyst system for the oligomerization of olefins, the stepsof the process comprising a) combining the source of chromium with atleast one ligating compound, optionally in the presence of at least onesolvent, b) isolating a ligating compound-chromium complex, c) combiningthe isolated a ligating compound-chromium complex with one or moreactivators.

In one embodiment, the invention provides a process to prepare acatalyst system for the oligomerization of olefins in theoligomerization reactor (in situ) or outside (ex situ) of theoligomerization reactor, optionally in the presence of at least oneoligomerization solvent and optionally in the presence of at least oneolefin, preferably in the presence of the at least one olefin,preferably ethylene, to be oligomerized. Preferably the source ofchromium, one or more activators, and at least onephosphacycle-containing ligating compound are contacted in theoligomerization reactor in any order. More preferably at least one,preferably one, ligating compound-chromium complex and one or moreactivators are contacted in the oligomerization reactor.

In the composition and process of the invention, the chromium (eitherfrom the source of chromium or from the ligating compound-chromiumcomplex), the one or more activators, and the phosphacycle-containingligating compound (including from the ligating compound-chromiumcomplex) may be in such proportions relative to each other to providechromium:ligating compound molar ratios from 10:1 to 1:10, morepreferably from 1.3:1 to 1:1.3, still more preferably from 1.1:1 to1:1.1; and chromium:activator (e.g., aluminum, boron, gallium compounds)molar ratios from 100:1 to 1:10,000, preferably from 1:1 to 1:3000, morepreferably from 1:1 to 1:1000, still more preferably from 1:1 to 1:500.

Typically the chromium (either from the source of chromium or from theligating compound-chromium complex), the one or more activators, and thephosphacycle-containing ligating compound (including from the ligatingcompound-chromium complex) are contacted (both in situ and ex situ) toprovide chromium:ligating compound molar ratios from 10:1 to 1:10, morepreferably from 1.3:1 to 1:1.3, still more preferably from 1.1:1 to1:1.1; and chromium:activator (e.g., aluminum, boron, gallium compounds)molar ratios from 100:1 to 1:10,000, preferably from 1:1 to 1:3000, morepreferably from 1:1 to 1:1000, still more preferably from 1:1 to 1:500.

The preparation of the catalyst system may be carried out attemperatures ranging from −80° C. to 110 preferably from 0° C. to 80°C., more preferably from 20° C. to 70° C. Hie optional at least onesolvent may be any inert solvent, especially inert solvents selectedfrom the group consisting of hydrocarbons, e.g., pentane, hexane,heptane, octane, nonane, decane, cyclohexane, cycloheptane,methylcyclopentane, methylcyclohexane, 1-hexene, 1-octene, benzene,toluene, xylene, ethylbenzene, cumene, mesitylene, or commercial s amrated hydrocarbons mixtures, such as Isopar-E™; neutral Lewis bases,e.g., THF, diethyl ether, alcohols, such as methanol or ethanol,acetonitrile; chlorinated hydrocarbons, e.g., chloroform, methylenechloride, dichloroethane, trichloroethane, tetrachloroethane,chlorobenzene, 1,2-dichlorobenzene; and ionic liquids, or mixturesthereof. Preferably the at least one solvent is selected from the groupconsisting of saturated hydrocarbons and chlorinated hydrocarbons ormixtures thereof. Especially preferred are methylcyclohexane,chlorobenzene, and 1,2-dichlorobenzene.

Activators

In some embodiments, the invention provides a process for selectivelyoligomerizing an olefin comprising an activated catalyst systemcomprising combining a) a source of chromium, b) one or more activators,and c) at least one phosphacycle-containing ligating compound.

An embodiment of the invention comprises a process for forming anactivated catalyst system comprising combining a) a source of chromium,b) one or more activators, and c) at least one phosphacycle-containingligating compound.

As is described below, the source of chromium, the one or moreactivators, and the ligating compound may be contacted in any order. Insome embodiments, the source of chromium and the ligating compound maybe contacted in the absence of any activators and a resulting ligatingcompound-chromium complex which may or may not be isolated is contactedwith one or more activators. In some embodiments, the ligating compoundmay be contacted with the one or more activators and the resultingcombination may be contacted with the chromium source. In an embodimentof the invention, an activating technique may be used in place of theone or more activators.

The activators (“activating co-catalysts”) and activating techniques aresuch as those that are known in the art for use with metal-based olefinpolymerization reactions. Suitable activators for use herein includeneutral Lewis acids, especially Group 13 metal and metalloid compounds;polymeric or oligomeric alumoxanes (also known as aluminoxanes);non-polymeric, non-coordinating, ion-forming compounds (including theuse of such compounds under oxidizing conditions); and aluminates. Asuitable activating technique is bulk electrolysis as disclosed in U.S.Pat. No. 6,465,384.

Preferred neutral Lewis acid activators are Group 13 metal and metalloidcompounds containing from 1 to 3 hydrocarbon derivative, preferablyhydrocarbyl, substituents as described herein, especially wherein theGroup 13 metal, and metalloid compounds are selected from compounds ofboron, aluminum, and gallium. More preferred Group 13 metal compoundsare (hydrocarbyl)aluminum, (hydrocarbyl)gallium, (hydrocarbyl)boron,(substituted hydrocarbyl)aluminum, (substituted hydrocarbyl)gallium and(substituted hydrocarbyl)boron compounds, especiallymono(hydrocarbyl)-substituted-aluminum,di(hydrocarbyl)-substituted-aluminum,tri(hydrocarbyl)-substituted-aluminum,(hydrocarbyl)-substituted-gallium, di(hydrocarbyl)-substituted-gallium,tri(hydrocarbyl)-gallium, or tri(hydrocarbyl)-boron compounds, moreespecially alkyl aluminum, alkyl gallium, aryl and arylalkyl boroncompounds or mixtures thereof. The term “alkyl aluminum” means amonoalkyl aluminum dihydride, monoalkylaluminum dihalide, ormonoalkylaluminum dialkoxide, a dialkyl aluminum hydride, dialkylaluminum halide, or a dialkyl aluminum alkoxide, or a trialkylaluminum.The term “alkyl gallium” means a monoalkyl gallium dihydride, monoalkylgallium dihalide, or monoalkyl gallium dialkoxide, a dialkyl galliumhydride, dialkyl gallium halide, or a dialkyl gallium alkoxide, or atrialkyl gallium. The term “aryl boron” means a monoaryl borondihydride, a monoaryl boron dihalide, a monoaryl boron dialkoxide, amonoaryl boron dialkyl, a diaryl boron alkyl, a diaryl boron hydride, adiaryl boron halide, a diaryl boron alkoxide, or a trialkyl boron. Theterm “arylalkyl boron” means a monoarylalkyl boron dihydride, amonoarylalkyl boron dihalide, a monoarylalkyl boron dialkoxide, amonoarylalkyl boron dialkyl, a diarylalkyl boron alkyl, a diarylalkylboron hydride, a diarylalkyl boron halide, a diarylalkyl boron alkoxide,or a triarylalkyl boron. Still more preferred are ((C₁₋₁₀)alkyl)aluminumdihydride, ((C₁₋₁₀)alkyl)aluminum dihalide, ((C₁₋₁₀)alkyl)aluminumdialkoxide, di((C₁₋₁₀)alkyl)aluminum hydride, di((C₁₋₁₀)alkyl)aluminumalkoxide, di((C₁₋₁₀)alkyl)aluminum halide, tri((C₁₋₁₀)alkyl)aluminum,((C₁₋₁₀)alkyl)gallium dihydride, ((C₁₋₁₀)alkyl)gallium dihalide,((C₁₋₁₀)alkyl)gallium dialkoxide, di((C₁₋₁₀)alkyl)gallium hydride,di((C₁₋₁₀)alkyl)gallium alkoxide, di((C₁₋₁₀)alkyl)gallium halide,tri((C₁₋₁₀)alkyl)gallium, ((C₆₋₁₈)aryl)boron dihydride,((C₆₋₁₈)aryl)boron dialkyl, ((C₆₋₁₈)aryl)boron dihalide,((C₆₋₁₈)aryl)boron dialkoxide, di((C₆₋₁₈)aryl)boron hydride,di((C₆₋₁₈)aryl)boron alkyl, di((C₆₋₁₈)aryl)boron halide,di((C₆₋₁₈)aryl)boron alkoxide, tri((C₆₋₁₈)aryl)aluminum,tri((C₆₋₁₈)aryl)boron, ((C₆₋₁₈)arylalkyl)boron dihydride,((C₆₋₁₈)arylalkyl)boron dialkyl, ((C₆₋₁₈)arylalkyl)boron dihalide,((C₆₋₁₈)arylalkyl)boron dialkoxide, di((C₆₋₁₈)arylalkyl)boron hydride,di((C₆₋₁₈)arylalkyl)boron alkyl, di((C₆₋₁₈)arylalkyl)boron halide,di((C₆₋₁₈)arylalkyl)boron alkoxide, tri((C₆₋₁₈)arylalkyl)aluminum,tri((C₆₋₁₈)arylalkyl)boron, or tri((C₆₋₁₈)aryl)gallium compounds andhalogenated (including perhalogenated) derivatives thereof, even moreespecially tris(fluoro-substituted phenyl)borane compounds,tris(fluoro-substituted phenyl)aluminum compounds, andtris(fluoro-substituted phenyl)gallium compounds, still even moreespecially tris(pentafluorophenyl)borane,tris(pentafluorophenyl)aluminum, and tris(pentafluorophenyl)gallium, ormixtures thereof.

Preferred alkyl aluminum activators include trimethylaluminum (TMA),triethylaluminum, tripropylaluminum, triisopropylaluminum,tributylaluminum, triisobutylaluminum (TIBA), trihexylaluminum,trioctylaluminum, ethyldiisopropylaluminum methylaluminum dichloride,ethylaluminum dichloride, isobutylaluminum dichloride, dimethylaluminumchloride, diethylaluminum chloride, diisobutylaluminum chloride,diethylaluminum hydride, diisobutylaluminum hydride, methylaluminumsesquichloride, ethylaluminum sesquichloride, isobutylaluminumsesquichloride, methylaluminum di(2,6-t-butyl-4-methylphenoxide),dimethylaluminum isopropoxide, diethylaluminum ethoxide,diisobutylaluminum (2,6-t-butyl-4-methylphenoxide), and mixturesthereof.

Preferred alkyl gallium compounds include trimethylgallium,triethylgallium, tripropylgallium, triisopropylgallium, diethylgalliumchloride, and dimethyl(2,4-pentanedionato)gallium.

Aluminoxanes and their preparations are known at, for example, U.S. Pat.No. 6,103,657. Aluminoxanes, a subset of (hydrocarbyl)aluminumcompounds, are well known in the art as typically polymeric oroligomeric, usually oligomeric, compounds which can be prepared by thecontrolled addition of water to a (hydrocarbyl)aluminum compound,especially an alkylaluminum compound, for example, trimethylaluminum.Examples of preferred polymeric or oligomeric alumoxanes aremethylaluminoxane (MAO) (MAO is also referred to as methalumoxane andmethylalumoxane in the literature), triisobutylaluminum-modifiedmethylalumoxane, and isobutylalumoxane, as well astetraethyl-μ-oxodialuminum and tetraisobutyl-μ-oxodialuminum.

Preferred alumoxanes are those which are commercially available so as toreduce costs. It will be recognized by those skilled in the art thatcommercially available alkylaluminoxanes may contain a proportion oftrialkylaluminum. For instance, commercial MAO usually containsapproximately 10 wt % trimethylaluminum (TMA), and commercial “modifiedMAO” (or “MMAO”) contains both TMA and TIBA. Preferred aluminoxanesinclude MAO and MMAO.

Preferred non-coordinating, ion-forming compounds, some of which aredescribed in WO 2007/039851, may include a cation and an anioncomponent, and may be represented by the following formula:

(Cat)^(d′+)A^(d′−)

where (Cat)^(d′+) is a cation having the charge d′+; A^(d′−) is anon-coordinating anion having the charge d′− and d′ is an integer from 1to 3.

A^(d′−) preferably can be a borate anion, especially an organoborateanion, an aluminate anion, a gallate anion, or a tantalate anion.Preferably d′ is 1; A^(d′−) is [A′(R⁹)₄]⁻, wherein A′ is boron,aluminum, or gallium, and; R⁹ independently at each occurrence isselected from the group consisting of hydride, halide, di(C₁₋₁₈)alkylamido, (C₁₋₁₈) hydrocarbyl, halosubstituted-(C₁₋₁₈) hydrocarbyl,(C₁₋₁₈) alkoxide, (C₂₋₁₈) aryloxide, and (C₂₋₁₈) arylalkyloxide.Preferably R⁹ is selected from (C₁₋₁₈) halosubstituted-alkyl, (C₂₋₁₈)halosubstituted-aryl, (C₂₋₁₈) halosubstituted-arylalkyl, (C₁₋₁₈)halosubstituted-alkoxide, (C₂₋₁₈) halosubstituted-aryloxide and (C₂₋₁₈)halosubstituted-arylalkyloxide. More preferably R₉ is selected from(C₁₋₁₈) fluorosubstituted-alkyl, (C₂₋₁₈) fluorosubstituted-aryl, (C₂₋₁₈)fluorosubstituted-arylalkyl, (C₁₋₁₈) fluorosubstituted-alkoxide, (C₂₋₁₈)fluorosubstituted-aryloxide, and (C₂₋₁₈)fluorosubstituted-arylalkyloxide. Preferably R₉ is selected from H, F,(CH₃)₂N, (CH₃CH₂)₂N, ((CH₃)₂CH)₂N, methyl, ethyl, propyl, isopropyl,butyl, isobutyl, phenyl, benzyl, trifluoromethyl, 2,2,2-trifluoroethyl,pentafluoroethyi, 1,1,1,3,3,3-hexafluoro-2-propyl,heptafluoro-isopropyl, nonafluoro-t-butyl, tetrafluorophenyl,pentafluorophenyl, 3,5-bis(trifluoromethyl)phenyl, methoxy, ethoxy,propoxy, isopropoxy, butoxy, phenoxy, trifluoromethoxy,2,2,2-trifluoroethoxy, pentafluoroethoxy,1,1,1,3,3,3-hexafluoro-2-propoxy, heptafluoro-isopropoxy,nonafluoro-t-butoxy, tetrafluorophenoxy, pentafluorophenoxy, or two R₉groups taken together are catechol or tetrafluorocatcchol. Preferably A′is boron; R₉ is H, fluoro, heptafluoro-isopropyl, nonafluoro-t-butyl,tetrafluorophenyl, pentafluorophenyl, or 3,5-bis(trifluoromethyl)phenyl;preferably at least one R₉ is fluoro, preferably at least one R₉ ispentafluorophenyl, more preferably at least two R₉ arepentafluorophenyl, even more preferably at least three R₉ arepentafluorophenyl, most preferably four R₉ are pentafluorophenyl.Preferably A′ is aluminum or gallium; R₉ is fluoro, pentafluorophenyl,3,5-bis(trifluoromethyl)phenyl, 1,1,1,3,3,3-hexafluoro-2-propoxy,heptafluoro-isopropoxy, nonafluoro-t-butoxy, pentafluorophenoxy, or twoR₉ groups taken together are tetrafluorocatcchol.

Illustrative, but non-limiting, examples of the anion component A^(d′−)are [B{OC(CF₃)₃}₄]⁻, [B(OC₆F₅)₄]⁻, [B(C₆F₄O₂)₂]⁻, [BF{OC(CF₃)₃}₃]⁻,[BH{OC(CF₃)₃}₃]⁻, [B{OC(CF₃)₃}₆]⁻, [B(OC₆F₅)₆]⁻, [B(C₆F₅)₄]⁻,[B{3,5-(CF₃)₂C₆H₃}₄]⁻, [BF(C₆F₅)₃]⁻, [BF{3,5-(CF₃)₂C₆H₃}₃]⁻,[Al{OCH(CF₃)₂}₄]⁻, [Al{OCF(CF₃)₂}₄]⁻, [Al{OC(CF₃)₃}₄]⁻, [Al(OC₆F₅)₄]⁻,[Al(C₆F₄O₂)₂]⁻, [AlF{OCH(CF₃)₂}₃]⁻, [AlF{OCF(CF₃)₂}₃]⁻,[AlF{OC(CF₃)₃}₃]⁻, [AlH{OC(CF₃)₃}₃]⁻, [Al₂F{OCH(CF₃)₂}₆]−,[Al₂F{OC(CF₃)₃}₆]⁻, [AlF(CF₃F₅)₃]⁻, [AlF{3,5-(CF₃)₂C₆H₃}₃]⁻,[Al(C₆F₅)₄]⁻, [Al{3,5-(CF₃)₂C₆H₃}₄]⁻, [Ga{OCH(CF₃)₂}₄]⁻,[Ga{OCF(CF₃)₂}₄]⁻, [Ga{OC(CF₃)₃}₄]⁻, [Ga(OC₆F₅)₄]⁻, [Ga(C₆F₄O₂)₂]⁻,[GaF{OCH(CF₃)₂]⁻, [GaF{OCF(CF₃)₂}₃]⁻, [GaF{OC(CF₃)₃}₃]⁻,[Ga₂F{OCH(CF₃)₂}₆]⁻, [Ga₂F{OC(CF₃)₃}₆]⁻, [GaF(C₆F₅)₃]⁻,[GaF{3,5-(CF₃)₂C₆H₃}₃]−, [Ga(C₆F₅)₄]⁻, [Ga{3,5-(CF₃)₂C₆H₃}₄]⁻, and[Ta(OC₆F₅)₆]⁻.

Preferably (Cat)^(d′+) can be represented by (L′-H)^(d′+), where L′ is aneutral Lewis base; H is hydrogen; (L′-H)^(d+) is a Brønsted acid havingthe charge d′+; and d′ is an integer from 1 to 3; preferably d′ is 1.More preferably (Cat)^(d′+) can be represented by

[(R)_(x′)L*-H]⁺ or [(R¹⁰)₃C]⁺ or [M]⁺

wherein the cation [(R)_(x′)L*-H]⁺ is a Brønsted acid with a +1 positivecharge; H is hydrogen; each R, independently chosen, is H, halide, C₂₋₂₀dialkylamido, C₁₋₂₀ hydrocarbyl, or C₁₋₂₀ heterohydrocarbyl; L* is anatom selected from the group consisting of N, P, and S; x′ is 3 for L*=Nor P and x′ is 2 for L*=S; the cation [(R¹⁰)₃C]⁺ is a carbenium cationwith a +1 positive charge; each R¹⁰, independently chosen, is H, C₁₋₂₀hydrocarbyl, or C₁₋₂₀ heterohydrocarbyl; the cation [M]⁺ is ametal-containing cation with a +1 positive charge.

Preferably R is independently a C₁₋₂₀ hydrocarbon derivative, or C₁₋₂₀heterohydrocarbon derivative, preferably C₁₋₂₀ hydrocarbyl, or C₁₋₂₀heterohydrocarbyl. Preferably L* is nitrogen; x′ is 3; at least one of Rcomprises at least 6 carbon atoms and provided further that the totalnumber of carbon atoms in (R)_(x′) collectively is greater than 12. Morepreferably at least one of R is a C₆₋₁₂ aryl, C₆₋₁₂ arylalkyl, or C₁₄₋₂₀alkyl. Preferably [(R)_(x′)L*-H]⁺ is bis((C₁₋₂₀)hydrocarbyl)ammonium ortris((C₁₋₂₀)hydrocarbyl)ammonium. As used herein, the term “ammonium”means a nitrogen cation that is ((C₁₋₂₀)hydrocarbyl)₄N⁺ (atetrakis((C₁₋₂₀)hydrocarbyl)ammonium cation), ((C₁₋₂₀)hydrocarbyl)₃N(H)⁺(a tris((C₁₋₂₀)hydrocarbyl)ammonium cation), ((C₁₋₂₀)hydrocarbyl)₂N(H)₂⁺ (a bis((C₁₋₂₀)hydrocarbyl)ammonium cation), ((C₁₋₂₀)hydrocarbyl)N(H)₃⁺ (a mono((C₁₋₂₀)hydrocarbyl)ammonium cation), or N(H)₄ ⁺ (ammoniumcation), wherein each (C₁₋₂₀)hydrocarbyl independently selected may bethe same or different Illustrative, but non-limiting, examples, of thecation component [(R)_(x′)L*-H]⁺ are di(octadecyl)ammonium,dimethylanilinium, dihexylanilinium, di(octadecyl)ammonium,methyldi(octadecyl)ammonium, (hexadecyl)(methyl)octadecylammonium,dimethylimidazolium, ethylmethylimidazolium, di-t-butylimidazolium,

Preferably R¹⁰ is C₁₋₁₂ alkyl, C₆₋₁₆ aryl, C₆₋₁₆ arylalkyl, or C₆₋₁₆heteroaryl. Preferably at least one R¹⁰ is substituted or unsubstitutedC₆₋₂₀ aryl, more preferably two R₁₀, independently selected, aresubstituted or unsubstituted C₆₋₂₀ aryl, even more preferably all threeR¹⁰, independently selected, are substituted or unsubstituted C₆₋₂₀aryl. Preferably R¹⁰ is phenyl, 4-methylphenyl, 2,4-dimethylphenyl,2,4,6-trimethylphenyl, 4-methoxyphenyl, 4-dimethylaminophenyl or2,6-dimethoxyphenyl. Preferably [(R¹⁰)₃C]⁺ is triphenylcarbenium(trityl).

Preferably the [M]⁺ metal-containing cation is Ag⁺ or a substituted orunsubstituted ferrocenium cation.

Preferred non-coordinating, ion-forming compounds (Cat)^(d+)A^(d′−)wherein d′=1 may be selected by pairing a desired (Cat)⁺ with a desiredA⁻, to give [(R)_(x′)L*-H]⁺ A⁻, [(R¹⁰)₃C]⁺ A⁻, or [M]⁺ A⁻. Illustrative,but non-limiting, examples of these non-coordinating, ion-formingcompounds include methyldi(octadecyl)ammoniumtetrakis(pentafluorophenyl)borate, dimethylaniliniumtetrakis(nonafluoro-t-butoxy)aluminate, trioctylammoniumtetrakis(pentafluorophenyl)borate,(hexadecyl)(methyl)(octadecyl)ammoniumtetrakis(pentafluorophenyl)borate,(hexadecyl)(methyl)(octadecyl)ammonium [B{3,5-(CF₃)₂C₆H₃}₄]⁻,ethylmethylimidazolium [Al{OCH(CF₃)₂}₄]⁻, triphenylcarbeniumtetrakis(tetrafluorophenyl)borate, ferrocenium [Ga(OC₆F₅)₄]⁻,tris(4-methoxyphenyl)carbenium [BF(C₆F₅)₃]⁻, and Ag⁺ [Ta(OC₆F₅)₆]⁻. Insome embodiments, organoboron activators represented as [(R)_(x′)L*-H]⁺[B(R₉)₄]⁻ are described in WO 2010/092554.

One or more activators are used to form the catalyst system with theligating compound and the source of chromium. Preferably at least twoactivators are used in combination. Also preferred are combinations ofsuch neutral Lewis acid mixtures with a polymeric or oligomericalumoxane, and combinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxane.In some embodiments, the at least two activators come from the sameclass (neutral Lewis acids with neutral Lewis acids; polymeric oroligomeric alumoxanes with polymeric or oligomeric alumoxanes;non-polymeric, non-coordinating, ion-forming compounds withnon-polymeric, non-coordinating, ion-forming compounds), for example,triethylaluminum with tris(pentafluorophenyl)borane; MAO with MMAO;methyldi(octadecyl)ammonium tetrakis(pentafluorophenyl)borate withtriphenylcarbenium tetrakis(nonafluoro-t-butoxy)aluminate; Ag⁺[Al(OC₆F₅)₄]⁻ with ferrocenium [B{3,5-(CF₃)₂C₆H₃}₄]⁻. More preferablythe at least two activators come from at least two different classes,for example, triethylaluminum with MMAO; diethylaluminum chloride withtriphenylcarbenium [Al{OCF(CF₃)₂}₄]⁻; MMAO with dimethylhexylammonium[Al{OCF(CF₃)₂}₄]⁻; MAO with methyldi(octadecyl)ammonium[B{3,5-(CF₃)₂C₆H₃}₄]⁻; triethylaluminum with MMAO andtetrakis(pentafluorophenyl)borate. Preferred combinations of activatorsinclude mixtures of neutral Lewis acids comprising a combination of atri((C₁₋₄)alkyl)aluminum and a halogenated tri((C₆₋₁₆)aryl)boroncompound, especially tris(pentafluorophenyl)borane. Combinations of oneor more of the foregoing activators and activating techniques are alsocontemplated.

The activators or combination of activators may be added to the reactionmedia (e.g., ethylene and/or diluents and/or solvent) at any time,either prior to the addition of the catalyst system or any componentsthereof, or at the same time as the catalyst system or any componentsthereof, or as part of the catalyst system, or after the catalyst systemor any components thereof have been added. Such techniques are known inthe art of oligomerization and are disclosed in more detail in forexample, U.S. Pat. Nos. 5,491,272; 5,750,817; 5,856,257; 5,910,619; and5,919,996, as well as WO 2008/146215 and WO 2007/007272. To the extentpermitted by US law, these references are incorporated herein.

Many activators and activating techniques have been previously taughtwith respect to different metal-ligand complexes in the following USPNs:U.S. Pat. No. 5,064,802; U.S. Pat. No. 5,153,157; U.S. Pat. No.5,296,433; U.S. Pat. No. 5,321,106; U.S. Pat. No. 5,350,723; U.S. Pat.No. 5,425,872; U.S. Pat. No. 5,625,087; U.S. Pat. No. 5,721,185; U.S.Pat. No. 5,783,512; U.S. Pat. No. 5,883,204; U.S. Pat. No. 5,919,983;U.S. Pat. No. 6,696,379; and U.S. Pat. No. 7,163,907. To the extentpermitted by US law, these references are incorporated herein. Examplesof suitable hydrocarbyloxides are disclosed in U.S. Pat. No. 5,296,433.Examples of suitable Brønsted acid salts for addition polymerizationcatalysts are disclosed in U.S. Pat. No. 5,064,802; U.S. Pat. No.5,919,983; U.S. Pat. No. 5,783,512. Examples of suitable salts of acationic oxidizing agent and a non-coordinating, compatible anion asactivators for addition polymerization catalysts are disclosed in U.S.Pat. No. 5,321,106. Examples of suitable carbenium salts as activatorsfor addition polymerization catalysts are disclosed in U.S. Pat. No.5,350,723. Examples of suitable silylium salts as activators foraddition polymerization catalysts are disclosed in U.S. Pat. No.5,625,087. Examples of suitable complexes of alcohols, mercaptans,silanols, and oximes with tris(pentafluorophenyl)borane are disclosed inU.S. Pat. No. 5,296,433. Some of these activators are also described ina portion of U.S. Pat. No. 6,515,155 BI beginning at column 50, at line39, and going through column 56, at line 55, only the portion of whichis incorporated by reference herein. Activators for olefinoligomerization may be selected from activators taught above for olefinpolymerization.

In the composition of the invention, the chromium (either from thesource of chromium or from the ligating compound-chromium complex), theone or more activators, and the phosphacycle-containing ligatingcompound (including from the ligating compound-chromium complex) may bein such proportions relative to each other to provide chromium:ligatingcompound molar ratios from about 10:1 to 1:10, more preferably fromabout 1.3:1 to 1:1.3, still more preferably from about 1.1:1 to 1:1.1;and chromium:activator (e.g., aluminum compounds, including aluminoxane,boron compounds, including borates, gallium compounds, non-coordinating,ion-forming compounds)) molar ratios from about 100:1 to 1:50,000,preferably from about 1:1 to 1:10,000, preferably from about 1:1 to1:3000, more preferably from about 1:1 to 1:1000, still more preferablyfrom about 1:1 to 1:500. In a particularly preferred embodiment when theactivator is selected from boron compounds or non-coordinating,ion-forming compounds, the chromium:activator molar ratios range fromabout 1:1 to 1:100, preferably, from about 1:1 to 1:10, more preferablyfrom about 1:1 to 1:2. In a particularly preferred embodiment when theactivator is selected from aluminum compounds, including aluminoxanecompounds, the chromium:activator molar ratios range from about 1:1 to1:10,000, preferably from abut 1:1 to 1:3000, more preferably from about1:1 to 1:1000, even more preferably from about 1:1 to 1:500.

When one or more alumoxanes alone or one or moretri((C₁₋₄)hydrocarbyl)aluminum compounds alone or together incombination are used as the activator, preferably the number of moles ofthe one or more alumoxanes or of the one or moretri((C₁₋₄)hydrocarbyl)aluminum compounds or of the one or morealumoxanes and the one or more tri((C₁₋₄)hydrocarbyl)aluminum compoundsused in combination that are employed is at least 100 times the numberof moles of the one or more sources of chromium or of the ligatingcompound-chromium complex. When tris(pentafluorophenyl)borane alone isused as the activator, preferably the number of moles of thetris(pentafluorophenyl)borane that are employed to the total number ofmoles of the one or more sources of chromium or of the ligatingcompound-chromium complex is from 0.5:1 to 10:1, more preferably from1:1 to 6:1, still more preferably from 1:1 to 5:1. The remainingactivators are generally employed in approximately mole quantities equalto or up to ten times the total mole quantities of the one or moresources of chromium or of the ligating compound-chromium complex.

The activator compound may optionally be a solid material, or besupported on an insoluble solid material, for example, aluminoxanes suchas MAO and borate activators may be supported on inorganic oxides suchas alumina, silica, MgCl₂ or the like.

The process may further include the use of activator compounds that mayact as reducing or oxidizing agents, such as sodium or zinc metal andthe like, (hydrocarbyl)zinc or (substituted hydrocarbyl)zinc compounds,(hydrocarbyl)magnesium or (substituted hydrocarbyl)magnesium compounds,hydrocarbyl- or substituted hydrocarbyllithium compounds, and the like,or oxygen-containing compounds, for example oxygen and the like, orchloride-containing compounds, for example methylene chloride,chloroform, and the like. Hydrocarbyl- and substituted hydrocarbylzinccompounds include monohydrocarbylzinc halide or alkoxide compounds anddihydrocarbylzinc compounds such as methylzinc chloride, ethylzincchloride, isopropylzinc bromide, 2-cyanoethylzinc bromide, allylzincchloride, cyclopentylzinc chloride, benzylzinc bromide, phenylzincchloride, isobutylzinc ethoxide, and propylzinc methoxide,4-dimethylaminophenylzinc bromide, bromo(2-ethoxy-2-oxoethyl)zincbromide, dimethylzinc, diethylzinc, divinylzinc, diallylzinc,dipropylzinc, diisopropylzinc, dibutylzinc, dioctylzinc, diphenylzinc,and dibenzylzinc. The process also includes the optional use of a zincspecies as an additive, as described in WO 2011/048527, which is hereinincorporated by reference.

Hydrocarbyl- and substituted hydrocarbylmagnesium compounds includemonohydrocarbylmagnesium halide or alkoxide compounds anddihydrocarbylmagnesium compounds such as methylmagnesium chloride,ethylmagnesium bromide, butylmagnesium iodide, propylmagnesium chloride,isopropylmagnesium chloride, phenylmagnesium bromide,4-dimethylaminophenylmagnesium bromide, benzylmagnesium butoxide,dibutylmagnesium, dioctylmagnesium, butylethylmagnesium,diisopropylmagnesium, dihexylmagnesium, and dibenzylmagnesium.

Hydrocarbyl- and substituted hydrocarbyllithium compounds includemethyllithium, ethyllithium, propyllithium, isopropyllithium,n-butyllithium, s-butyllithium, i-butyllithium, t-butyllithium,pentyllithium, 2,2-methylpropyllithium, hexyllithium, octyllithium,2-ethylhexyllithium, allyllithium, propynyllidiium, vinyllithium,phenyllithium, cyclopentyllithium, cyclohexyllithium, benzyllithium,4-dimethylaminophenyllithium, and 4-methoxyphenyl lithium.

Mixtures of the foregoing hydrocarbyl- and substituted hydrocarbylzinccompounds, hydrocarbyl- and substituted hydrocarbylmagnesium compounds,and hydrocarbyl- and substituted hydrocarbyllithim compounds are alsoenvisioned, especially in combination with alkylaluminum compounds.

A further advantageous use of the activator compounds is to exert abeneficial effect of scavenging contaminants such as adventitious oxygenor water that may be present.

Oligomerization Process

In some embodiments, the invention provides a process for selectivelyoligomerizing an olefin comprising placing at least one olefin inoperative contact with a catalyst system as described above underconditions sufficient to convert at least a portion of the at least oneolefin to at least one oligomer of the at least one olefin, the catalystsystem comprising, a) a source of chromium, b) one or more activators,and c) at least one phosphacycle-containing ligating compound asdescribed herein. As described above, the catalyst system may comprisean isolated ligating compound-chromium complex. The components of thecatalyst system may be contacted in any order.

The oligomerization process includes a process for the trimerizationand/or tetramerisation of at least one olefin, preferably at least oneα-olefin. In one embodiment, two or more different types of ligands maybe used to alter the relative amounts of 1-hexene and 1-octene beingproduced. For example, one or more ligands that produce predominantly1-hexene may be used in combination with one or more ligands thatproduce predominantly 1-octene in order to achieve a specific1-hexene:1-octene production ratio.

The at least one olefin to be oligomerized may comprise a single olefinor mixture of olefins. In one embodiment of the invention it maycomprise a single olefin. The olefin may include multiple carbon-carbondouble bonds, but preferably it comprises a single carbon-carbon doublebond. The at least one olefin may comprise an α-olefin with 2 to 30carbon atoms, preferably 2 to 10 carbon atoms. In the process of theinvention, the at least one olefin to be oligomerized may be selectedfrom the group comprising ethylene (ethene), propylene (propene),1-butene, isobutene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene,1-decene, 1-dodecene, 2-methyl-1-propene, 3-methyl-1-butene,3-methyl-1-pentene, 4-methyl-1-pentene, styrene, p-methyl styrene, ormixtures thereof. Preferably the at least one olefin comprises ethylene,propylene, 1-hexene, or 1-octene, more preferably ethylene. Mixtures ofolefins may be used to form mixed oligomeric products, preferablyethylene in combination with 1-hexene and/or 1-octene. The productstream comprises the oligomeric products that are formed according tothe invention.

Preferably the at least one oligomer comprises hexene or octene,preferably a mixture of 1-octene and 1-hexene. The ratio of the mass ofhexene or octene, preferably a mixture of 1-octene and 1-hexene, formedin the oligomerization process to the total mass of reaction products(product stream) of the oligomerization process (weight fraction) rangesfrom ten percent by weight to 100 percent by weight, preferably from 50percent by weight to 100 percent by weight, more preferably from 70percent by weight to 100 percent by weight, even more preferably from 80percent by weight to 100 percent by weight, still even more preferablyfrom 85 percent by weight to 100 percent by weight, most preferably from90 percent by weight to 100 percent by weight.

The 1-hexene:1-octene ratio by weight may be selected by the choice ofcatalyst system and oligomerization conditions and ranges from 1000:1 to1:1000, preferably from 100:1 to 1:100, more preferably from 10:1 to1:10, even more preferably from 4:1 to 1:10, even still more preferablyfrom 2:1 to 1:5. The 1-hexene:1-octene ratio by weight may range from1000:1 to 100:1; from 100:1 to 10:1; and from 10:1 to 3:1; preferablyfrom 3:1 to 2:1; from 2:1 to 1:1; and from 1:1 to 1:2; more preferablyfrom 1:2 to 1:3; and from 1:3 to 1:4; even more preferably from 1:4 to1:10; from 1:10 to 1:100; and from 1:100 to 1:1000.

The reaction products of the oligomerization process may, depending onthe nature of the catalyst system and the reaction conditions, inaddition to 1-hexene and 1-octene, also comprise different quantities ofpolymer byproduct (“polymer”, e.g., olefin waxes, polyethylene); cyclicsand C₆ and C₈ isomers (for example, methylcyclopentane,methylenecyclopentane, allylcyclopentane, propylcyclopentane, orhexadiene); specific higher oligomers, especially C₁₀₋₁₈ olefinoligomers, which may arise from the mixed oligomerization of ethylene,1-hexene, or 1-octene. The amount of polymer byproduct produced in thetrimerization and tetramerization of ethylene using the process of thepresent invention is typically at most about 10 wt %. Lower levels ofsolid olefin waxes and polyethylene, including as low as none, producedin the trimerization and tetramerization of ethylene are desirable incommercial operations as this can reduce the amount of fouling of thereactor equipment, reduce the amount of waste by-products and reduce theamount of operational “downtime” due to maintenance and cleaning of thereactor equipment. Preferably the polymer byproduct has a total massfraction with respect to the total mass of reaction products within arange of zero percent by weight to 10 percent by weight, preferably fromzero percent by weight to five percent by weight, and more preferablyfrom zero percent by weight to two percent, by weight, even morepreferably from zero percent by weight to one percent by weight, mostpreferably from zero percent by weight to one-half of one percent byweight.

In an embodiment, the oligomerization can be carried out in the presenceof additives to control selectivity, enhance activity and reduce theamount of polymer formed in the oligomerization process. In anembodiment, hydrogen (H₂), silanes, a halide source (especially thehalide sources disclosed in U.S. Pat. No. 7,786,336, Zhang et al.), andthe like may be used in the catalytic composition or otherwiseintroduced into the process. In some embodiments, the amount of polymerproduced in the method to oligomerize olefins can be reduced byproviding and/or controlling a partial pressure or concentration ofhydrogen, silanes, and/or a halide source to the olefin productionprocess. While it should be noted that the presence of hydrogen,silanes, and/or a halide source is not necessarily required to producean oligomerization product having an acceptable quantity of polymer, theamount of polymer produced by the oligomerization process may be furtherreduced by the presence of hydrogen, silanes, and/or a halide source.Other (optional) additives include antistatic agents (such as thepolysulfone polymer sold under the trademark Stadis®) and/orfluorocarbons to mitigate reaction fouling. The use of hydrogen isespecially preferred.

The oligomer product as described herein, may be prepared using thedisclosed catalyst system in a homogeneous liquid phase reaction in thepresence or absence of an inert solvent, and/or in a slurry reactionwhere the catalyst system is in a form that displays little or nosolubility, and/or in a two-phase liquid/liquid reaction, and/or in abulk phase reaction in which neat reagent and/or product olefins serveas the dominant medium, and/or in a gas phase reaction, usingconventional equipment and contacting techniques.

The oligomerization process may be carried out in an inert solvent ormixture of inert solvents. The inert solvent or mixture of inertsolvents is sometimes referred to as the makeup solvent. An inertsolvent is one that does not interfere substantially with theoligomerization process, especially inert solvents selected from thegroup consisting of hydrocarbons, e.g., butane, pentane, hexane,heptane, octane, nonane, decane, cyclohexane, methylcyclopentane,methylcyclohexane, 1-hexene, 1-octene, benzene, toluene, xylene,ethylbenzene, mesitylene, cumene, or commercial saturated hydrocarbonsmixtures, such as Isopar-E™, particularly saturated C₆-C₁₀ (acyclic andcyclic) hydrocarbons such as pentane, hexane, heptane, octane,Isopar-E™, cyclopentane, cyclohexane, methylcyclohexane; neutral Lewisbases, e.g., THF, diethyl ether, acetonitrile; chlorinated hydrocarbons,e.g., chloroform, methylene chloride, dichloroethane, trichloroethane,tetrachloroethane, chlorobenzene, 1,2-dichlorobenzene; and ionicliquids. Preferably the inert solvent or mixture of inert solvents isselected from the group consisting of saturated hydrocarbons andchlorinated hydrocarbons or mixtures thereof. Especially preferred arecyclohexane, methylcyclohexane, chlorobenzene, and 1,2-dichlorobenzene.Mixtures of the foregoing are also suitable.

The makeup solvent may be introduced into the oligomerization reactor inthe form of a feed stream comprising the olefin to be oligomerized ormay be added separately.

According to another aspect of the invention there is provided a processfor the oligomerization of olefins wherein the product of theoligomerization process is an olefin or mixture of olefins, especially1-hexene and 1-octene, and makes up more than 30 wt % of the productstream of the process based on the weight of the product stream.

In one aspect of the process of the invention, an olefinic feed stream(“feed stream”) comprising at least one olefin to be oligomerized isprovided, wherein the at least one olefin is selected from the groupcomprising ethylene (ethene), propylene (propene), 1-butene, isobutene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,1-dodecene, 2-methyl-1-propene, 3-methyl-1-butene, 3-methyl-pentene,4-methyl-1-pentene, styrene, p-methyl styrene, or mixtures thereof.Preferably the at least one olefin comprises ethylene, propylene,1-hexene, or 1-octene, more preferably ethylene.

According to another aspect of the invention the oligomerization processincludes the step of contacting a feed stream comprising the olefin tobe oligomerized with the catalyst system as described above and whereinthe product or product stream of the oligomerization process comprisesan olefin or mixture of olefins, especially 1-hexene and/or 1-octene,and the olefin or mixture of olefins, especially 1-hexene and/or1-octene, makes up from 10 wt % to 100 wt %, preferably from 20 wt % to100 wt %, preferably from 30 wt % to 100 wt %, preferably from 40 wt %to 100 wt %, preferably from 50 wt % to 100 wt %, preferably from 60 wt% to 100 wt %, preferably from 85 wt % to 100 wt % of the the totalproduct formed or product stream of the process, wherein the productstream of the process comprises the reaction products of theoligomerization process, catalyst system residues, optional solvent, andany optional additives employed in the process.

The feed stream comprising the olefin to be oligomerized can beintroduced into the process according to the invention in a continuousor batch fashion. The feed stream can be introduced into the process ineither liquid or gaseous form. In addition to the olefin to beoligomerized, the feed stream may comprise makeup solvent and componentsfrom the recycle stream. The recycle stream may comprise recycledsolvent, recycled olefin, as well as various recycled oligomerizationproducts, including 1-hexene, 1-octene, methylcyclopentane,methylenecyclopentane, higher oligomers which may arise from the mixedoligomerization of ethylene, 1-hexene, or 1-octene, and polymer.Preferably the recycle stream does not comprise polymer, or comprisesonly de minimis amounts of polymer.

If desired, at least some of the components from the recycle stream maybe introduced into the process separately from the feed stream or,alternatively, at least some of the components from the recycle streammay be introduced into the process together with the feed stream.Preferably the at least one olefin to be oligomerized makes up from 5 wt% to 100 wt % of the feed stream, preferably from 20 wt % to 100 wt % ofthe feed stream, more preferably from 50 wt % to 100 wt % of the feedstream, even more preferably from 75 wt % to 100 wt % of the feedstream, still more preferably from 90 wt % to 100 wt % of the feedstream, and yet even more preferably from 95 wt % to 100 wt % of thefeed stream based on total weight of the feed stream, not including thesolvent.

The oligomerization process may be carried out at pressures fromatmospheric to 50 000 kPa (500 barg). Ethylene pressures in the range of1000-7000 kPa (10-70 barg) are preferred. Particularly preferredpressures range from 3000-5000 kPa (30-50 barg). The oligomerizationprocess may be carried out at temperatures from −100° C. to 250° C.,preferably at temperatures from 15° C. to 130° C., more preferably attemperatures from 35° C. to 100° C., still more preferably from 40° C.to 90° C., even still more preferably from 50° C. to 80° C.

Although the catalyst system, its individual components, reagents,solvents, and reaction products may be employed on a once-through basis,any of these materials can, and are indeed preferred to be recycled tosome extent in order to minimize production costs, especially withregard to the solvents and unreacted olefins to be oligomerized.

In an embodiment of the invention, the catalyst system or its individualcomponents, in accordance with the invention, may also be immobilized bysupporting it on a support material, for example, silica, alumina,zirconia, titania, MgCl₂, NaCl, zeolites, clays, including artificialhectorite or smectorite clays such as Laponite™ RD, carbon, e.g.,graphite, grapheme, or carbon black, or mixtures thereof, or on apolymer, for example polyethylene, polypropylene, polystyrene, orpoly(aminostyrene). An advantage of an immobilized catalyst system isthat the oligomerization process can be carried out such that the feedstream and the product stream flow continuously or semi-continuouslythrough the reactor, while the catalyst system remains substantially inthe reactor. The catalyst system can be formed in situ in the presenceof the support material, or the support can be pre-impregnated orpremixed, simultaneously or sequentially, with one or more of thecomponents of the catalyst system or the oligomerization catalyst. Insome cases the support material can also act as a component of theactivator. This approach would also facilitate the recovery of thecatalyst system or any of its components from the reaction mixture forreuse. The concept was, for example, successfully demonstrated with achromium-based ethylene trimerization catalyst by T. Monoi and Y.Sasaki, J. Mol. Cat. A: Chem., 2002, 787, 135-141. In some cases thesupport can also act as a catalyst system component, for example wheresuch supports contain aluminoxane functionalities or other activators orwhere the support is capable of performing similar chemical functions asan activator. In an embodiment of the invention, the immobilization onthe support may include chemical bonding of the phosphacycle-containingligating compound with the support, for example, via a functional group.The phosphacycle-containing ligating compound may include a polymericmoiety to render the catalyst system or the reaction product of thesource of chromium and the said ligating compound to be soluble athigher temperatures and insoluble at lower temperatures, e.g. 25° C.This approach may enable the recovery of the complex from the reactionmixture for reuse and has been used for other catalyst as described byD. E. Bergbreiter et al., J. Am. Chem. Soc., 1987, 109, 177-179. In asimilar vein the catalyst system or the ligating compound can also beimmobilized by binding the catalyst system or the ligating compound tosilica, silica gel, polysiloxane or alumina backbone as, for example,demonstrated by C. Yuanyin et al., Chinese J. React. Pol., 1992, 1(2),152-159 for immobilizing platinum complexes.

An embodiment of the invention is a phosphacycle-containing ligatingcompound-containing polymeric support (e.g., polystyrene (PS),poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA)) havingamino- or phosphino functionality present by means of which thephosphacycle-containing ligating compound is chemically bonded to thepolymeric support. In a non-limiting example the phosphacycle-containingligating compound-containing polymeric support can be formed in that thenitrogen atom of the dihydroaminoalkyl group of adihydroaminoalkyl-functionalized PS, PPM, or PMA support is incorporatedinto the Y group of a phosphacycle-containing ligating compound. Inanother non-limiting example, a phosphacycle-containing ligatingcompound-containing polymeric support is formed upon polymerization of avinylaryl, methacrylate, or acrylate monomer functionalized with aphosphacycle-containing ligating compound. An embodiment of theinvention is a supported catalyst system comprising aphosphacycle-containing ligating compound-containing polymeric support,a source of chromium, and at least one activator. In an embodiment ofthe invention the supported catalyst system can be formed by contactinga phosphacycle-containing ligating compound-containing polymeric supportwith a source of chromium and at least one activator.

In some embodiments, the invention provides a tandem oligomerization,preferably trimerization and/or tetramerization, and polymerizationprocess wherein the olefin in the form of ethylene is oligomerized usingthe catalyst system of the invention to produce a monomer mixturecomprising monomers selected from 1-hexene and 1-octene and at least onemonomer from the mixture is copolymerized in situ with ethylene usingthe polymerization catalyst and wherein oligomerization andpolymerization take place in the same reaction medium.

In some embodiments, the invention provides a polymerization processwherein the feed stream of the polymerization process comprises at leastpart of the oligomer product of the oligomerization process.

The oligomerization process of the invention may be carried out in aplant which includes any type of reactor, especially a mixed reactor.Examples of such reactors include, but are not limited to, batchreactors, semi-batch reactors and continuous reactors. The plant mayinclude, in combination a) a reactor, b) at least one inlet line intothis reactor for olefin reactant and the catalyst system, c) effluentlines from this reactor for oligomerization reaction products, and d) atleast one separator to separate the desired oligomerization reactionproducts, wherein the catalyst system comprises a source of chromium, aphosphacycle-containing ligating compound, and at least one activator,as described herein. The term “mixed reactor” is meant to convey itsconventional meaning—i.e., a reactor that contains an agitator or mixingsystem. A continuously stirred tank reactor (“CSTR”) is generallypreferred. However, a loop reactor in which mixing is provided by acirculating pump is also suitable (and such reactors are well known tothose skilled in the art and are in commercial use). The use of a CSTRis generally preferred as it is desirable to maintain essentiallyhomogenous reactor conditions—i.e., as will be appreciated by thoseskilled ill the art, a well-mixed CSTR will provide homogenous reactorconditions (in contrast to a plug flow, or tubular reactor, in which thereactor conditions are typically very different at the inlet anddischarge). More than one CSTR may be used.

Although a single CSTR is preferred, it is also within the scope of thisinvention to (optionally) use an additional tubular reactor. If thetubular reactor is employed, it would be placed downstream of the CSTR.The tubular reactor (if used) would provide some additional ethyleneconversion, thereby reducing the need to recover/recycle ethylene fromthe discharge.

The term “continuous flow” is meant to convey its conventionalmeaning—i.e. reactants are continuously added to the reactor and productis continuously withdrawn.

In another embodiment of the process the reactor and a separator may becontacted to facilitate the simultaneous formation of reaction productsand separation of these compounds from the reactor. This processprinciple is commonly known as reactive distillation. When the catalystsystem exhibits no solubility in the solvent or reaction products, andis fixed in the reactor so that it does not exit the reactor with thereactor product, solvent and unreacted olefin, the process principle iscommonly known as catalytic distillation.

As described herein, the catalyst system may be formed in situ in thereactor or may be preformed outside of the reactor and then added intothe reactor. Advantageously the oligomerization process may be carriedout under inert conditions, that is, under substantial absence of oxygenand/or other species which interfere with the oligomerization process.

While not wishing to be bound by theory, it is believed that the1-hexene and/or 1-octene that are produced during the reaction maythemselves become reactants for a secondary reaction that may producethe C₁₀₊ oligomers that are formed under the conditions of the process.In one embodiment of the invention, the oligomerization process may formspecific higher C₁₀₋₁₈ olefin oligomers which arise from the mixedoligomerization of ethylene, 1-hexene, or 1-octene. While such C₁₀₋₁₈oligomers can be used in making surfactants for aqueous detergentformulations, most of the C₁₀₊ oligomers have comparatively low value soit is desirable to limit the amount of them that is produced.

In an embodiment of the process of the invention, product selectivitycan be improved in a continuous process using certain specificconditions. More specifically, selectivity can be increased by using alow chromium concentration and by maintaining low 1-hexene and/or1-octene concentrations in the reactor. Further improvements may beachieved using lower oligomerization temperatures, so low temperaturesare preferred (even though a low temperature is not “sufficient” for acontinuous process). Low temperatures are preferred in order to increasethe 1-octene:1-hexene ratio. In this embodiment, the present inventionprovides: A continuous flow process for the oligomerization of ethylene,said process comprising I) adding ethylene and solvent to a mixedreactor and contacting said ethylene under oligomerization conditionswith a catalyst system as described above; II) removing a productdischarge stream comprising 1-hexene, 1-octene, C₁₀₊ oligomers, solvent,and optional polymer from said reactor; and III) controlling the flow ofsaid solvent to said reactor such that the product discharge streamcontains from 1 to 30 combined weight % of 1-hexene and 1-octene,preferably from 2 to 25 combined weight % of 1-hexene and 1-octene, morepreferably from 3 to 20 combined weight % of 1-hexene and 1-octene basedon the weight of the product discharge stream (reaction products of theoligomerization process, catalyst system residues, solvent, and anyoptional additives employed in the process) wherein said process isfurther characterized by being conducted at a catalyst concentration offrom 0.01 to 50 micromolar Cr, preferably 0.05 to 20 micromolar Cr, morepreferably 0.1 to 5 micromolar Cr. Another preferred element of thisembodiment of the present invention is the use of ethyleneconcentrations, based on vapor-liquid equilibrium, of 3 to 15 weight %,especially from 5 to 10 weight %.

As noted above, this embodiment of the process of the invention requiresthat the 1-octene concentration in the reactor is controlled/limited. Ina continuous flow process, the concentration of 1-octene in the reactorcan be controlled by adjusting the solvent flow rate and the rate ofreaction. For example, increasing the solvent flow will dilute the1-octene concentration and decreasing the catalyst concentration willdecrease the rate of reaction. Low catalyst concentrations (less than50×10⁻⁶ moles of Cr per liter, preferably less than 5×10⁻⁶ moles of Crper titer) are required in this process and low temperatures arepreferred wherein the reactor temperature is preferably from 25 to 100°C., more preferably from 35 to 85° C., even more preferably from 40 to70° C. Suitable solvents include the solvents described above,particularly saturated C₆-C₂₀ (acyclic and cyclic) hydrocarbons such aspentane, hexane, heptane, octane, Isopar-E™, cyclopentane, cyclohexane,methylcyclohexane, and unsubstituted and substituted aromatichydrocarbons such as toluene, xylene, ethylbenzene, cumene, mesitylene,chlorobenzene, and dichlorobenzene.

For safety and or product quality reasons it is often desirable todeactivate the catalyst system at some point in the oligomerizationprocess, for example, alter completion of a desired level ofoligomerization or in case of a runaway reaction. In an embodiment ofthe invention, the catalyst system will be deactivated upon completionof the oligomerization either in the reactor, upon its leaving thereactor or shortly thereafter. In general, many polar compounds (such aswater, alcohols and carboxylic acids) will deactivate the catalyst. Theuse of alcohols, amines and/or carboxylic acids is preferred—andcombinations of these are contemplated. Preferred deactivators includewater, methanol, ethanol, propanol, butanol, methylamine, dimethylamine,ethylamine, diethylamine, propylamine, dipropylamine, butylamine,dibutylamine, formic acid, acetic acid, propanoic acid, or butanoicacid. It is generally found that the quantity employed to deactivate thecatalyst is sufficient to provide a deactivator to metal (fromcatalyst+activator) mole ratio between about 0.1 to about 4, especiallyfrom 1 to 2 (thus, when MAO is the activator, the deactivator isprovided on a ratio based on moles of Cr+moles of Al). The deactivatormay be added to the oligomerization product stream before or after thevolatile unreacted reagents/diluents and product components areseparated. In the event of a runaway reaction (e.g., rapid temperaturerise) the deactivator can be immediately fed to the oligomerizationreactor to terminate the reaction. The deactivation system may alsoinclude a basic compound (such as sodium hydroxide) to minimizeisomerization of the products (as deactivation conditions may facilitatethe isomerization of desirable alpha olefins to undesired internalolefins).

Polymer removal (and, optionally, catalyst removal) preferably followscatalyst deactivation. Two types of polymer may exist, namely polymerthat is dissolved in the process solvent and non-dissolved polymer thatis present as a solid or “slurry”.

Solid/non-dissolved polymer may be separated using one or more of thefollowing types of equipment: centrifuge; cyclone (or hydrocyclone), adecanter equipped with a skimmer or a filter. Preferred equipmentinclude so-called “self-cleaning filters” sold under the name V-autostrainers, self-cleaning screens such as those sold by Johnson ScreensInc. of New Brighton, Minn. and centrifuges such as those sold by AlfaLaval Inc. of Richmond, Va. (including those sold under the trademarkSharpies®).

Soluble polymer may be separated from the final product by two distinctoperations. Firstly, low molecular weight polymer that remains solublein the heaviest product fraction (C₂₀₊) may be left in that fraction.This fraction will be recovered as “bottoms” from the distillationoperations (described below). This solution may be used as a fuel for apower generation system.

An alternative polymer separation comprises polymer precipitation causedby the removal of the solvent from the solution, followed by recovery ofthe precipitated polymer using a conventional extruder. The technologyrequired for such separation/recovery is well known to those skilled inthe art of solution polymerization and is widely disclosed in theliterature.

In another embodiment, the residual catalyst is treated with an additivethat causes some or all of the catalyst to precipitate. The precipitatedcatalyst is preferably removed from the product at the same time asby-product polymer is removed (and optionally using the same equipment).Many of the catalyst deactivators listed above will also cause catalystprecipitation. In a preferred embodiment, a solid sorbent (such as clay,silica or alumina) is added to the deactivation operation to facilitateremoval of the deactivated catalyst by filtration or centrifugation.

Reactor fouling (caused by deposition of polymer and/or catalystresidue) can, if severe enough, cause the process to be shut down forcleaning. The deposits may be removed by known means, especially the useof high pressure water jets or the use of a hot solvent flush. The useof an aromatic solvent (such as chlorobenzene) for solvent flushing isgenerally preferred because they are good solvents for polyethylene.

The invention will now be further described by means of the followingnon-limiting examples.

EXAMPLES

All preparation reactions carried out at temperatures below −50° C. wereconducted outside of a glovebox under inert atmosphere using Schlenkline techniques. All preparation reactions carried out under elevatedpressure were conducted outside of a glovebox. Depending on the elevatedpressure preparation reaction, the reactor involved may have beencharged in a glovebox. Unless otherwise specified, all other reactionswere conducted in inert (nitrogen or argon) atmosphere gloveboxes. Allcommercial chemicals were obtained from Sigma-Aldrich Corporation, AcrosOrganics, Strem Corporation, Oakwood Chemical, Oxchem Corporation, orThermo Fisher Scientific, Inc.

Solvents used in the preparation reactions were purified as follows:Non-chlorinated solvents (e.g., tetrahydrofuran (THF), toluene, hexane,diethyl ether) were purified in a manner similar to the method ofPangborn et ah (“Safe and Convenient Procedure for Solvent Purification”Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.; Timmers,F. J. Organometallics 1996, 15, 1518-1520) by passing the degassedsolvents through columns of activated A204 alumina and supportedcopper-based reactive scavenger (Q5 reactant) to remove water and traceoxygen, respectively. Other solvents (pentane, methylene chloride,chloroform, chlorobenzene) were dried by storing over activatedmolecular sieves or by passing through activated A2 alumina. Thesolvents were stored over activated molecular sieves. The A2 alumina andA204 alumina were activated by heating under a dry nitrogen stream at300° C. for 8 h. The molecular sieves were activated by heating under adry nitrogen stream at 250° C. for 4 h.

Ambient temperature within the gloveboxes may vary within the range of25 degrees centigrade (° C.) to 30° C. Unless otherwise specified, theNMR data was obtained at room temperature with a Varian 400 MHz or 500MHz apparatus. The multiplicity and coupling constants of the peaks fromthe NMR spectra, based on appearance and obtained by first orderanalysis, are reported as follows: s, singlet; d, doublet; t, triplet;q, quartet; p, pentet. In some cases the spectra may be second order.The unit for “grams” is abbreviated as “g”; the unit for “millimoles” isabbreviated as “mmol”.

Experimental Information for Phosphacycle Ligands and their Cr ComplexesLigating Compound Preparation Examples Preparation of((rac)-N-(diphenylphosphanyl)-N-methyl-2,5-diphenylphospholan-1-amine),L553 Step 1. Preparation of1-[(N,N)-dimethylamino]-1-r-oxo-2-t,5-t-diphenyl-phosphol-3-ene

In a glovebox, a 200-mL jar was charged with aluminum chloride (22.84 g,171.3 mmol) and 50 ml, of anhydrous methylene chloride. The jar wasplaced in a freezer at −30° C. for 15 minutes then removed.Dimethylphosphoramidous dichloride (25.00 g, 171.3 mmol) was added to astirred suspension. Once everything was dissolved, the jar was removedfrom the glovebox and the contents transferred to a 500-mL three-neckedround bottom flask equipped with an addition funnel and nitrogen inlet.The flask and its contents were cooled in an ice bath.1,4-Diphenylbutadiene (32.12 g, 155.7 mmol) was dissolved in anhydrousmethylene chloride (˜200 mL) in the glovebox, transferred to theaddition funnel, and slowly added under nitrogen atmosphere to thereaction mixture over a 45 minute period. After 1 h, reaction completionwas shown by ³¹P NMR spectroscopy. The solution was transferred to anaddition funnel and added slowly to a chilled mixture of NTA(nitrilotriaceric acid) (37.21 g, 194.6 mmol) in 300 mL of aqueoussaturated NaHCO₃ solution. The biphasic mixture was stirred vigorouslyfor 1 h at 0° C. while under nitrogen and checked by ³¹P NMRspectroscopy for completion. Once complete the mixture was filteredthrough Celite and transferred to a separatory funnel. The organic layerwas separated. The aqueous layer was extracted with methylene chloride(2×100 mL). The organic layers were washed with saturated NaHCO₃ (100mL), 1 M HCl (100 mL), and brine (100 mL), dried over MgSO₄,concentrated down and dried to yield the product as a light orangesolid. Yield (42.2 g, 91.3%). The product was stored in a drybox. ¹H NMR(400 MHz, C₆D₆) δ 7.23 (ddt, J=8.1, 2.3, 1.2 Hz, 4H), 7.09 (tq, J=6.8,0.8 Hz, 4H), 7.04-6.98 (m, 2H), 6.09 (dd, J=27.9, 1.0 Hz, 2H), 4.26-4.14(m, 2H), 1.81 (d, J=8.1 Hz, 6H), ¹³C NMR (101 MHz, C₆D₆) δ 136.91 (d,J=8.2 Hz), 131.05 (d, J=15.8 Hz), 129.01 (d, J=2.6 Hz), 127.71 (d, J=4.7Hz), 127.15 (d, J=2.7 Hz), 50.09, 49.38, 36.47 (d, J=1.5 Hz). ³¹P NMR(162 MHz, C₆D₆) δ 66.51.

Step 2. Preparation of1-[(N,N)-dimethylamino]-1-r-oxo-2-t,5-t-diphenyl-phospholane

In a reaction not carried out in a glovebox, a clean, leak-tested,250-mL pressure reactor equipped with a bottom filter was charged with1-[(N,N)-dimethylamino]-1-r-oxo-2-t,5-t-diphenyl-phosphol-3-ene (37.00g, 124.4 mmol), 5% Pd—C (3.973 g, 37.33 mmol), and methanol (˜150 mL).The reactor was pressurized to 700 pounds per square inch (psi) (4.83megapascals (MPa)) with hydrogen gas and heated to 60° C. with 700 rpmstirring. After 2.5 hours the reaction was sampled and the conversionwas analyzed by ³¹P NMR spectroscopy to be 91%. The reactor wasrepressurized with hydrogen to 708 psi (4.88 MPa) and the reaction wasallowed to continue overnight. The reaction mixture was checked again at22 hours and determined to be complete. The reactor was emptied into around bottom flask through a bottom filter yielding a clear, pale yellowsolution. The reactor was washed out with methanol (2×20 mL) and thosewashings also collected. The combined solutions were concentrated downto yield the product as a light yellow solid. Yield (35.6 g, 95.4%). ¹HNMR (400 MHz. C₆D₆) δ 1.25-7.21 (m, 4H), 7.15-7.08 (m, 4H), 7.02 (tt,J=7.3, 1.5 Hz, 2H), 3.55 (dt, J=22.7, 7.5 Hz, 2H), 2.20-1.87 (m, 4H),1.76 (dd, J=8.1, 1.6 Hz, 6H). ¹³C NMR (101 MHz, C₆D₆) δ 138.15 (d, J=5.5Hz), 128.92 (d, J=2.0 Hz), 127.68 (d, J=4.9 Hz), 126.76 (d, J=2.4 Hz),46.53, 45.81, 35.82 (d, J=2.3 Hz), 26.80 (d, J=12.9 Hz). ³¹P NMR (162MHz, C₆D₆) δ 63.80.

Step 3. Preparation of (rac)-1-(dimethylamino)-2,5-diphenylphospholane1-oxide

A 400-mL jar was charged with1-[(N,N)-dimethylamino]-1-r-oxo-2-t,5-t-diphenyl-phospholane (35.00 g,116.9 mmol), methanol (250 mL), and a stir bar and placed in a freezer afew hours. The cold jar was removed from the freezer, a thermocouple wasadded to the jar, and a 25 wt % solution of sodium methoxide in methanol(63.16 g, 292.3 mmol) (2.5 equivalents) was added slowly whilemonitoring the temperature to avoid a large exotherm. The reactiontemperature started at −12° C. and rose to −3° C. by the end of theaddition. After the reactants had dissolved (5 minutes), an aliquot wasremoved for analysis. The sample was treated with a few drops of 1 M HCland extracted with toluene. The solution was concentrated and analyzedby ³¹P NMR which showed reaction was 33% converted to the desiredproduct. The reaction was checked again after 2 hours and was determinedto be 75% convened to the desired product. After 4 hours total reactiontime the reaction was sampled again and determined to be complete. Thereaction mixture was removed from the glovebox, hydrolyzed slowly withHCl (1 M, 150 mL), and extracted with toluene. The organic layers werewashed with water and brine, dried over anhydrous magnesium sulfate,filtered and concentrated to yield the product as a light yellow solid.Yield (28.7 g, 82.0%). ¹H NMR (400 MHz, C₆D₆) δ 7.42 (dddd, J=8.3, 1.8,1.2, 0.5 Hz, 2H), 7.25-7.21 (m, 2H), 7.18-7.09 (m, 4H), 7.10-7.01 (m,2H), 3.49 (ddd, J=24.5, 12.9, 7.5 Hz, 1H), 2.91-2.80 (m, 1H), 2.05 (d,J=8.8 Hz, 6H), 1.99-1.84 (m, 3H), 1.62-1.48 (m, 1H), ¹³C NMR (101 MHz,C₆D₆) δ 137.82 (dd, J=30.4, 4.9 Hz), 129.56 (d, J=5.1 Hz), 128.57 (dd,J=5.9, 1.9 Hz), 127.44 (d, J=5.0 Hz), 126.82 (d, J=2.0 Hz), 126.46 (d,J=2.6 Hz), 48.07, 47.33, 43.08, 42.31, 35.69 (d, J=2.4 Hz), 30.36 (d,J=11.8 Hz), 27.30 (d, J=9.0 Hz). ³¹P NMR (162 MHz, C₅D₆) δ 56.39.

Step 4. Preparation of (rac)-1-chloro-2,5-diphenylphospholane

(rac)-1-(Dimethylamino)-2,5-diphenylphospholane 1-oxide (12.0 g, 40.1mmol) was mixed in toluene (125 mL). Pyridine (4.05 mL, 50.1 mmol) andtrichlorosilane (4.50 mL, 44.1 mmol) were added and the mixture wasstirred overnight (˜24 h) at ambient temperature. Pentane (20 mL) wasadded to the resulting slurry and the mixture was filtered through adisposable fritted filter. The filtrate was concentrated to dryness. Theresulting yellow oil was dissolved in acetonitrile (anhydrous grade,stored over molecular sieves, 140 mL) and washed with pentane (2×30 mL).The acetonitrile layer was then concentrated to dryness. The liquid wasthen dissolved in hexanes (50 mL) and passed through a small plug ofacidic alumina. The alumina was rinsed with another 40 mL of hexanes.The filtrate was concentrated to yield the product as a yellow liquid.Yield (6.1 g, 84%). ¹H NMR (400 MHz, C₆D₆) δ 7.21-6.91 (m, 10H), 3.69(td, J=8.8, 2.3 Hz, 1H), 3.06 (ddd, J=33.4, 12.3, 5.7 Hz, 1H), 2.44-2.18(m, 2H), 2.05-1.90 (m, 1H); 1.58-1.43 (m, 1H). ¹³C NMR (101 MHz, C₆D₆) δ141.93 (d, J=19.6 Hz), 137.09, 129.06, 128.55, 128.27 (d, J=44.7 Hz),126.80 (d, J=2.3 Hz), 58.18 (d, J=32.2 Hz), 53.66 (d, J=32.9 Hz), 34.70(d, J=2.7 Hz), 31.93 (d, J=3.2 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 137.59.

Step 5. Preparation of (rac)-N-butyl-2,5-diphenylphospholan-1-amine

A solution of (rac)-1-chloro-2,5-diphenylphospholane (5.30 g, 19.2 mmol)in hexanes (50 mL) was added to n-butylamine (5.72 mL, 57.8 mmol) in 150mL of hexanes. After stirring for 30 minutes, a sample was removed forNMR spectroscopic analysis. Analysis showed complete conversion to thedesired product. The resulting slurry was filtered through a plug ofneutral alumina. The alumina was rinsed with an additional 25 mL ofhexanes. The filtrate was concentrated under vacuum to yield the productas a light yellow oil. Yield (5.9 g, 98%). ¹H NMR (400 MHz, C₆D₆) δ 7.26(dt, J=8.0, 1.6 Hz, 2H), 7.20-7.06 (m, 6H), 7.06-6.96 (m, 2H), 3.00(ddd, J=21.7, 12.5, 6.0 Hz, 1H), 2.87 (dt, J=12.6, 6.6 Hz, 1H),2.43-2.26 (m, 1H), 2.22-2.04 (m, 2H), 2.01 (qd, J=7.2, 5.5 Hz, 1H), 1.78(qdd, J=12.5, 5.1, 2.6 Hz, 1H), 1.52 (qdd, J=12.6, 5.1, 2.5 Hz, 1H),1.03-0.93 (m, 1H), 0.92-0.74 (m, 4H), 0.61 (t, J=7.1 Hz, 3H), ¹³C NMR(101 MHz, C₆D₆) δ 144.33 (d, J=18.3 Hz), 140.20, 128.69 (d), 128.45 (d,J=1.3 Hz), 128.20 (d, J=3.4 Hz), 127.92, 125.74 (dd, J=37.2, 2.2 Hz),55.75 (d, J=14.3 Hz), 50.39 (d, J=23.1 Hz), 47.67 (d, J=22.6 Hz), 35.43(d, J=6.6 Hz), 34.18 (d, J=2.7 Hz), 31.71 (d, J=2.2 Hz), 19.98, 14.05.³¹P NMR (162 MHz, C₆D₆) δ 73.36.

Step 6. Preparation of(rac)-N-(diphenylphosphanyl)-N-methyl-2,5-diphenylphospholan-1-amine,L553

(rac)-N-Butyl-2,5-diphenylphospholan-1-amine (0.25 g, 0.93 mmol) andtriethylamine (142 uL, 1.02 mmol) were dissolved in toluene (5 mL).Iododiphenylphosphine (0.29 g, 0.93 mmol) was also dissolved in toluene(5 mL). The two solutions were cooled in the freezer to −30° C. Theiododiphenylphosphine solution was added dropwise to the solution of(rac)-N-butyl-2,5-diphenylphospholan-1-amine and triethylamine causingimmediate solid formation. The sample was analyzed by ³¹P-NMR whichshowed complete conversion to the product. The solution was filtered andthe filtrate was concentrated under reduced pressure. The residue wasdissolved in ether (15 mL) and filtered again before concentrating to athick yellow oil. Pentane (5 mL) was added to the oil, the solution wasstirred for 1 minute, and then concentrated again, yielding the desiredproduct as a white solid. Yield (3.8 g, 94%). ¹H NMR (400 MHz, C₆D₆) δ7.53-7.38 (m, 4H), 7.37-7.20 (m, 4H), 7.20-7.04 (m, 8H), 7.04-6.84 (m,5H), 4.08 (ddt, J=12.1, 7.5, 4.5 Hz, 1H), 3.35 (ddd, J=23.9, 13.2, 5.6Hz, 1H), 3.23-2.85 (m, 3H), 2.56-2.34 (m, 1H), 2.32-2.10 (m, 1H),1.76-1.46 (m, 1H), 0.83-0.51 (m, 3H), 0.43 (d, J=14.2 Hz, 3H), ¹³C NMR(101 MHz, C₆D₆) δ 144.40 (d, J=21.0 Hz), 140.58 (d, J=22.2 Hz), 139.18(d, J=2.4 Hz), 138.55 (d, J=16.6 Hz), 133.10 (d, J=20.2 Hz), 132.07 (d,J=20.1 Hz), 128.84 (dd, J=3.5, 1.7 Hz), 128.46, 128.32 (t, J=4.8 Hz),128.21-128.03 (m), 127.60, 127.54, 55.48 (dd, J=21.9, 18.5 Hz), 54.29(dd, J=31.8, 4.8 Hz), 51.82 (dd, J=22.9, 3.4 Hz), 36.64 (d, J=2.3 Hz),33.58 (d, J=6.5 Hz), 32.87 (dd, J=7.7, 3.4 Hz), 19.59, 13.40. ³¹P NMR(162 MHz, C₆D₆) δ 98.98 (d, J=23.5 Hz), 57.64 (d, J=23.4 Hz). HRMS(ESI-TOF) m/z: [M+H]+ Calcd for C₃₂H₃₅NP₂ 496.2318; Found 496.2327.

Preparation of(rac)-N-butyl-N-(diethylphosphanyl)-2,5-diphenylphospholan-1-amine, L565Preparation of(rac)-N-butyl-N-(diethylphosphanyl)-2,5-diphenylphospholan-1-amine, L565

(rac)-N-Butyl-2,5-diphenylphospholan-1-amine (0.25 g, 0.80 mmol) andtriethylamine (112 μL, 0.80 mmol) were combined with toluene (3 mL).Chlorodiethylphosphine (98 μL, 0.80 mmol) was added and the cloudymixture was stirred for 2 h at room temperature. ³¹P NMR spectroscopyindicated complete conversion to the product. Volatiles were removedunder vacuum and the residue mixed with ether and passed through a smallplug of activated neutral alumina. Volatiles were removed from thefiltrate to yield the product as a colorless oil. Yield (0.27 g, 84%).¹H NMR (400 MHz, C₆D₆) δ 7.47-7.32 (m, 4H), 7.22 (dt, J=15.8, 7.7 Hz,4H), 7.15-7.00 (m, 2H), 3.88 (ddt, J=11.8, 7.8, 4.1 Hz, 1H), 3.29 (ddd,J=24.4, 13.1, 5.8 Hz, 1H), 2.97-2.58 (m, 3H), 2.51-2.32 (m, 1H), 2.12(tt, J=10.6, 5.3 Hz, 1H), 1.75-1.50 (m, 1H), 1.50-1.28 (m, 2H),1.27-0.90 (m, 8H), 0.86-0.63 (m, 6H), 0.64-0.44 (m, 1H), ¹³C NMR (101MHz, C₆D₆) δ 144.65 (d, J=21.2 Hz), 140.45 (d, J=2.6 Hz), 128.86 (dd,J=3.5, 1.7 Hz), 128.73, 128.64, 128.36, 126.09 (d, J=2.4 Hz), 125.60 (d,J=1.9 Hz), 54.29 (dd, J=21.5, 13.6 Hz), 51.73 (dd, J=24.4, 1.9 Hz),50.90 (dd, J=23.3, 3.4 Hz), 36.39 (d, J=3.5 Hz), 35.32 (dd, J=5.8, 2.5Hz), 32.86 (dd, J=6.4, 3.1 Hz), 23.63-22.02 (m), 20.44, 14.19, 10.48 (d,J=17.1 Hz), 9.53 (d, J=24.0 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 92.21 (s,br), 60.09 (d, J=19.2 Hz). HRMS (ESI-TOF) m/z: [M+H]+ Calcd forC₂₄H₃₅NP₂ 400.2318; Found 400.2310.

Preparation ofrac-N-butyl-N-(bis(4-methylphenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L592 Step 1. Preparation of bis(4-methylphenyl)iodophosphine

Iodotrimethylsilane (0.50 g, 2.5 mmol) was added to a solution ofbis(4-methylphenyl)chloro phosphine (0.50 g, 2.0 mmol) in toluene (5.0mL). The orange mixture was stirred at ambient conditions overnight. Thereaction mixture was filtered to remove the dark precipitate which wassuspended in the solution after the reaction. The solvent and unreactediodotrimethylsilane were removed under vacuum and the product wasobtained as a yellowish liquid. Yield (0.50 g, 73%). ¹H NMR (400 MHz,C₆D₆) δ 7.53 (t, 4H), 6.76 (m, 4H), 1.91 (d, J=0.9 Hz, 6H). ¹³C NMR (101MHz, C₆D₆) δ 140.37, 134.08 (d, J=23.3 Hz), 129.60 (d, J=6.5 Hz), 21.07.³¹P NMR (162 MHz, C₆D₆) δ 43.08 (s).

Step 2. Preparation ofrac-N-butyl-N-(bis(4-methylphenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L592

A cold solution (−30° C.) of triethylamine (0.089 g, 0.88 mmol) intoluene-d₈ (2.0 mL) was added to a cold (−30° C.) solution ofrac-N-butyl-2,5-diphenylphospholan-1-amine (0.28 g, 0.88 mmol) intoluene-ds (2.0 mL) and the resulting reaction mixture was stirred for10 min. The reaction mixture was placed in a freezer at −30° C. for 30minutes. To this cooled reaction mixture was added a cold (−30° C.)solution of the bis(4-methylphenyl)iodophosphine (0.30 g, 0.88 mmol) in2.0 mL of toluene-d₈ with formation of a white precipitate. The reactionmixture was stirred for 30 min at ambient temperature. Volatiles wereThe volatiles were removed under vacuum. The crude product was dissolvedin toluene (10 mL). The solution was passed through 5-cm plug ofactivated neutral alumina and the volatiles were removed under vacuum,giving solid product which was recrystallized from cold pentane at −30°C. to produce pure product. Yield 0.20 g (43%). ¹H NMR (400 MHz, C₆D₆) δ7.45 (dt, J=7.1, 1.2 Hz, 2H), 7.37-7.31 (m, 2H), 7.29 (dt, J=8.0, 1.4Hz, 2H), 7.23-7.10 (m, 5H), 7.04 (ddt, J=7.9, 6.8, 1.3 Hz, 2H),6.98-6.92 (m, 2H), 6.87-6.77 (m, 3H), 4.09 (m, 1H), 3.41-3.26 (m, 1H),3.16-2.87 (m, 3H), 2.52-2.32 (m, 1H), 2.16 (m, 1H), 2.05 (s, 3H), 2.00(s, 3H), 1.66-1.43 (m, 1H), 0.94 (m, 1H), 0.61 (m, 3H), 0.40 (t, J=7.0Hz, 3H). ¹³C NMR (101 MHz, C₆D₆) δ 144.89 (d, J=21.3 Hz), 139.65 (d,J=2.2 Hz), 138.21 (d, J=13.5 Hz), 137.76 (d, J=21.0 Hz), 135.79 (d,J=15.6 Hz), 133.61 (d, J=20.5 Hz), 132.45 (d, J=20.1 Hz), 129.35-129.08(m), 128.75 (d, J=4.3 Hz), 128.71-128.58 (m), 128.46, 125.97 (d, J=2.5Hz), 125.61 (d, J=1.8 Hz), 55.62 (dd, J=21.8, 18.7 Hz), 54.48 (dd,J=31.9, 4.9 Hz), 52.29 (dd, J=22.9, 3.3 Hz), 36.97 (d, J=2.2 Hz),34.33-33.06 (m), 21.15 (d, J=3.4 Hz), 19.99, 13.75. ³¹P NMR (162 MHz,C₆D₆) δ 99.33 (d, J=22.8 Hz), 57.72 (d, J=22.8 Hz).

Preparation ofN-butyl-N-((2S,5S)-2,5-diphenylphospholan-1-yl)-10,11-dihydro-5H-dibenzo[b,f]-phosphepin-5-amine,L593 Step 1. Preparation of 1,2-bis(2-bromophenyl)ethane

A solution of 2-bromobenzyl bromide (33.36 g, 133.5 mmol) in THF (200mL) was cooled in a dry ice bath to −78° C. n-Butyllithium (1.42 M, 47.0mL, 66.7 mmol) was added slowly dropwise over 40 minutes. The solutionwas allowed to stir for about 3 hours, then gradually allowed to warmup. When the temperature reached about −20° C., water (40 mL) was slowlyadded and the reaction mixture was allowed to warm to ambienttemperature. Workup: The organic solution was washed with water (3×250mL) and sat. aq. NaCl solution (125 mL). The combined organics weredried over anhydrous magnesium sulfate. The solution was filtered, andconcentrated (rotavap) to give a white solid. The proton and carbon NMRspectra of this crude product agree with the literature. The product wasrecrystallized from hot hexane to give 18.48 g, 81.4%, in a first crop.Second crop: 2.62 g. Total: 21.10 g, 92.97%. ¹H NMR (400 MHz, CDCl₃) δ7.55 (dd, J=7.8, 1.1 Hz, 2H), 7.24-7.17 (m, 4H), 7.07 (ddd, J=8.0, 6.7,2.4 Hz, 2H), 3.05 (s, 4H), ¹³C NMR (101 MHz, CDCl₃) δ 140.54, 132.77,130.60, 127.79, 127.41, 124.46, 36.42.

Step 2. Preparation of 1,2-bis(2-lithiophenyl)ethane-diethyl etheradduct

n-Butyllithium (16.5 mL, 2.44 M, 40.3 mmol) was slowly added to asolution of 1,2-bis(2-bromophenyl)ethane (6.540, 19.23 mmol) in ether(80 mL) cooled in a dry ice bath (precipitate forms). The reactionmixture was allowed to warm to ambient temperature and was stirredovernight. The resulting white precipitate was filtered out, washed witheither and dried to give a white powder (4.5606 g, 88.4%, based on themonoether adduct, as shown by the ¹H NMR spectrum). ¹H NMR (500 MHz,THF-d₈) δ 7.86 (dd, J=6.2, 1.2 Hz, 2H), 6.80 (d, J=7.2 Hz, 2H), 6.72(td, J=7.2, 1.8 Hz, 2H), 6.67 (ddd, J=7.3, 6.3, 1.3 Hz, 2H), 3.39 (q,J=7.0 Hz, 4H), 3.07 (s, 4H), 1.15-1.09 (m, 6H). ¹³C NMR (126 MHz,THF-d₈) δ 185.70, 158.67, 143.91, 125.48, 124.03, 122.34, 66.30, 43.46,15.68.

Step 3. Preparation ofN,N-dimethyl-10,11-dihydro-5H-dibenzo[b,f]phosphepin-5-amine

The dilithium salt 1,2-bis(2-lithiophenyl)ethane-diethyl ether adduct(4.000 g, 14.86 mmol) was suspended in ether (60 mL) and cooled to −30°C. in the freezer. Dimethylphosphoramidous dichloride (2.17 g, 14.86mmol) was added slowly dropwise and the reaction mixture was allowed towarm to ambient temperature and stir overnight. The ³¹P NMR spectrumshowed very little starting NMe₂PCl₂ compound to be present along with amajor peak at 75 ppm, presumably due to the desired product. Thevolatiles were removed under reduced pressure. The white residue wasextracted with copious amounts of hexane, filtered, and the volatileswere removed under reduced pressure to give a white solid having lowsolubility in hexane. The solids were dissolved in hot hexane andallowed to cool while standing at ambient temperature. Large crystalsformed. The supernatant was pipetted off, the residue was washed with 3mL of hexane, and the solids were dried under reduced pressure (2.231 g,58.8%). By ³¹P NMR the compound was about 85% pure, with about 15% ofother phosphorus species being present. ¹H NMR (400 MHz, CDCl₃) δ 7.38(td, J=7.3, 1.6 Hz, 2H), 7.24 (tt, J=7.5, 1.5 Hz, 2H), 7.19 (tdd, J=7.2,1.6, 0.6 Hz, 2H), 7.12 (ddd, J=7.3, 3.8, 1.0 Hz, 2H), 3.41-3.29 (m, 2H),3.06-2.97 (m, 2H), 2.96 (d, J=8.0 Hz, 6H). ¹³C NMR (101 MHz, CDCl₃) δ143.14 (d, J=13.8 Hz), 139.86 (d, J=18.0 Hz), 129.59 (d, J=2.3 Hz),129.34 (d, J=11.0 Hz), 127.22 (d, J=1.0 Hz), 125.51 (d, J=3.2 Hz), 43.23(d, J=16.7 Hz), 34.20 (d, J=7.2 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 72.90.

Step 4. Preparation of 5-chloro-10,11-dihydro-5H-dibenzo[b,f]phosphepin

Anhydrous HCl (15 mL, 2.0 M, ether solution, 30.0 mmol) was added to asolution of the solids from Step 3 immediately above comprising mostlyN,N-dimethyl-10,11-dihydro-5H-dibenzo[b,f]phosphepin-5-amine dissolvedin a mixture of hexane (60 mL) and ether (40 mL) with immediateformation of precipitate. The mixture was stirred for several hours. ¹Hand ³¹P NMR spectra showed the reaction has not quite gone tocompletion, however the mixture is cleaner than it started out: The 15%of other species is gone and only desired P—Cl product and starting P—Nare present. Additional HCl solution (5 mL) was added. The reactionmixture was filtered and the volatiles were removed under reducedpressure to give white solid which was washed with hexane and driedunder reduced pressure. By NMR it is about 85% pure, so it wasrecrystallized from boiling ether. The solution was allowed to cool toambient temperature overnight. The supernatant was pipetted from thecrystalline material which had formed and the product was dried underreduced pressure. Yield of colorless crystals/powder was about 1.24 g,33.84%, of 95% pure material. An additional less-pure crop was obtainedfrom the supernatant. ¹H NMR (500 MHz, CDCl₃) δ 7.87 (ddd, J=13.3, 7.6,1.5 Hz, 1H), 7.37 (td, J=7.5, 1.4 Hz, 1H), 7.28 (tt, J=7.5, 1.5 Hz, 1H),7.22 (dt, J=7.6, 1.7 Hz, 1H), 3.64-3.55 (m, 1H), 3.28-3.19 (m, 1H), ¹³CNMR (126 MHz, CDCl₃) δ 144.71 (d, J=4.8 Hz), 135.80 (d, J=37.2 Hz),134.17 (d, J=46.4 Hz), 131.07, 130.15, 126.13 (d, J=13.3 Hz), 34.03 (d,J=5.1 Hz). ³¹P NMR (202 MHz, CDCl₃) δ 92.26.

Step 5. Preparation of 5-iodo-10,11-dihydro-5H-dibenzo[b,f]phosphepin

Iodotrimethylsilane (1.30 g, 6.54 mmol) was added quickly drop wise to asolution of 5-chloro-10,11-dihydro-5H-dibenzo[b,f]phosphepin (1.24 g,5.03 mmol) in toluene (50 mL). The reaction solution immediately turnedyellow. The solution was stirred for several hours. By ³¹P NMR, thereaction was complete. The volatiles were removed under reduced pressureto give the product as a bright yellow powder, Yield: 1.7641 g, 103.8%,of product which by ³¹P NMR is 97% pure. ¹H NMR (500 MHz, CDCl₃) δ 7.83(dd, J=17.2, 7.6 Hz, 2H), 7.37 (t, J=7.3 Hz, 3H), 7.28-7.16 (m, 4H),3.76 (s, 2H), 3.28 (s, 3H). ¹³C NMR (126 MHz, CDCl₃) δ 147.26 (d, J=2.3Hz), 135.67 (d, 63.7 Hz), 132.67 (d, J=41.5 Hz), 131.86, 130.43, 125.93(d, J=18.5 Hz), 34.65. ³¹P NMR (202 MHz, CDCl₃) δ 38.80.

Step 6. Preparation ofN-butyl-N-((2S,5S)-2,5-diphenylphospholan-1-yl)-10,11-dihydro-5H-dibenzo[b,f]-phosphepin-5-amine,L593

A solution of N-butyl-2,5-diphenylphospholan-1-amine (0.186 g, 0.60mmol) and triethylamine (0.301 g, 2.98 mmol) in toluene (10 mL) wascooled in the freezer for several hours.5-Iodo-10,11-dihydro-5H-dibenzo[b,f]phosphepin (0.201 g, 0.60 mmol) wasadded dropwise. The yellow color of the5-Iodo-10,11-dihydro-5H-dibenzo[b,f]phosphepin disappeared quickly andprecipitate gradually formed. The reaction mixture was stirredovernight. The mixture was filtered and the volatiles were removed underreduced pressure to give a viscous oil that solidified oil standingunder reduced pressure overnight. The yield was 0.3195 g, 103%. Theproduct looked good on the basis of its ³¹P NMR spectrum. ¹H NMR (400MHz, CDCl₃) δ 7.45 (d, J=7.4 Hz, 2H), 7.40-7.29 (m, 4H), 7.28-7.22 (m,4H), 7.22-7.15 (m, 2H), 7.14-6.96 (m, 4H), 6.71 (dt, J=14.9, 1.7 Hz,1H), 6.34 (t, J=7.4 Hz, 1H), 4.08-3.96 (m, 1H), 3.56 (dddd, J=24.6,14.3, 5.8, 2.0 Hz, 1H), 3.36 (ddd, J=16.2, 9.4, 7.0 Hz, 2H), 2.99 (tdd,J=15.0, 7.4, 4.4 Hz, 4H), 2.66-2.50 (m, 2H), 2.35 (tq, J=10.7, 5.3, 4.5Hz, 1H), 1.84-1.64 (m, 2H), 1.09 (dq, J=16.8, 6.7, 5.0 Hz, 1H),1.01-0.90 (m, 1H), 0.90-0.79 (m, 1H), 0.66 (t, J=7.3 Hz, 3H), ¹³C NMR(101 MHz, CDCl₃) δ 144.80 (d, J=21.8 Hz), 143.45 (d, J=14.7 Hz), 142.88(d, J=14.1 Hz), 138.79 (d, J=2.0 Hz), 138.42 (d, J=27.0 Hz), 136.97 (d,J=23.0 Hz), 130.98 (d, J=3.0 Hz), 130.87 (d, J=2.2 Hz), 129.38 (d, J=1.6Hz), 129.14 (d, J=1.9 Hz), 128.74 (dd, J=3.3, 1.6 Hz), 128.64 (d, J=9.5Hz), 128.44, 128.38 (d, J=1.4 Hz), 127.58 (d, J=1.3 Hz), 126.84, 125.79(d, J=2.6 Hz), 125.73 (d, J=1.9 Hz), 125.47 (d, J=2.3 Hz), 124.96 (d,J=2.8 Hz), 54.89 (d, J=2.6 Hz), 54.74 (d, J=12.5 Hz), 54.58 (dd, J=15.2,7.7 Hz), 52.63 (dd, J=22.1, 3.1 Hz), 37.77 (d, J=1.8 Hz), 34.42 (dd,J=10.6, 7.3 Hz), 33.73 (d, J=14.0 Hz), 32.84 (dd, J=8.0, 3.4 Hz), 20.23,13.80. ³¹P NMR (162 MHz, CDCl₃) δ 97.48, 72.33. High resolution massspec: Expected (M+1) 522.2473; Found (M+1) 522.2494

Preparation of(rac)-N-(bis(4-(trifluoromethyl)phenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L594 Step 1. Preparation of bis(4-(trifluoromethyl)phenyl)iodophosphine

Bis(4-(trifluoromethyl)phenyl)chlorophosphine (0.55 g, 1.5 mmol) wasdissolved in toluene (3.0 mL). Iodotrimethylsilane (0.26 mL, 1.9 mmol)was added and the orange solution was stirred at ambient temperature for2 h. A dark oily material formed during the reaction. The reactionmixture was decanted to remove the dark material and the volatiles wereremoved to yield the product as a pale yellow oil. Yield (0.42 g, 61%).¹H NMR (400 MHz, C₆D₆) δ 7.32-7.20 (m, 4H), 7.19-7.09 (m, 4H), ¹³C NMR(101 MHz, C₆D₆) δ 139.55 (d, J=40.6 Hz), 134.24 (d, J=23.6 Hz), 132.24(d, J=32.7 Hz), 131.96 (d, J=10.7 Hz), 125.66 (dd, J=6.2, 3.6 Hz). ³¹PNMR (162 MHz, C₆D₆) δ 29.46-29.26 (m).

Step 2. Preparation of(rac)-N-(bis(4-(trifluoromethyl)phenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L594

(rac)-N-Butyl-2,5-diphenylphospholan-1-amine (0.14 g, 0.45 mmol) andtriethyl amine (69 uL, 0.50 mmol) were combined and dissolved in toluene(2.0 mL). Bis(4-(trifluoromethyl)phenyl)iodophosphine (0.20 g, 0.45mmol) was separately dissolved in toluene (2.0 mL). The two solutionswere cooled in the freezer to −30° C. Thebis(4-(trifluoromethyl)phenyl)iodophosphine solution was added dropwiseto the solution of (rac)-N-butyl-2,5-diphenylphospholan-1-amine andtriethylamine causing immediate solid formation. After 30 minutes, thevolatiles were removed under vacuum. The material was extracted withether and filtered through a small alumina plug. The solvent was removedto yield the crude product Pentane was added to the solid and themixture was placed in the freezer at −30° C. After 1.5 h, the pentanewas decanted from the solid product and the process was repeated withcold pentane. The residual solvent was removed under reduced pressure toyield the product as a white solid. Yield (0.16 g, 56%). ¹H NMR (400MHz, C₆D₆) δ 7.28-7.17 (m, 6H), 7.16-6.87 (m, 10H), 6.71-6.55 (m, 2H),3.88-3.66 (m, 1H), 3.20 (ddd, J=24.9, 13.2, 5.8 Hz, 1H), 3.01-2.61 (m,3H), 2.43-2.18 (m, 1H), 2.05 (tt, J=10.8, 5.3 Hz, 2H), 1.58-1.34 (m,1H), 1.07-0.76 (m, 1H), 0.76-0.50 (m, 3H), 0.44-0.31 (m, 3H), ¹³C NMR(101 MHz, C₆D₆) δ 144.87 (d, J=24.5 Hz), 143.78 (d, J=20.7 Hz), 143.16(d, J=19.8 Hz), 139.10 (d, J=2.7 Hz), 133.35 (d, J=20.8 Hz), 132.77 (d,J=20.7 Hz), 130.82 (dd, J=38.3, 32.4 Hz), 129.08-128.96 (m), 128.92,128.69, 128.59, 126.56 (d, J=2.5 Hz), 126.07 (d, J=1.8 Hz), 125.27 (dd,J=5.4, 3.9 Hz), 124.83 (dd, J=6.1, 3.7 Hz), 123.49 (d, J=8.1 Hz),56.68-55.17 (m), 54.82 (d, J=26.0 Hz), 51.45 (dd, J=23.1, 3.6 Hz), 36.83(d, J=3.4 Hz), 34.50-33.77 (m), 33.19 (dd, J=6.1, 3.4 Hz), 19.96, 13.69.³¹P NMR (162 MHz, C₆D₆) δ 98.44 (d, J=20.9 Hz), 57.13 (d, J=20.5 Hz).¹⁹F NMR (376 MHz, C₆D₆) δ −62.56 (d, J=20.7 Hz). HRMS (ESI-TOF) m/z:[M+H]+ Calcd for C₃₄H₃₃F₆NP₂ 632.2065; Found 632.2080.

Preparation ofrac-(2R,5R)—N-butyl-N-((2R,5R)-2,5-diphenylphospholan-1-yl)-2,5-diphenylphospholan-1-amine,L596 Step 1. Preparation of rac-(2R,5R)-1-iodo-2,5-diphenylphospholane

(2S,5S)-1-Chloro-2,5-diphenylphospholane (2.0 g, 7.28 mmol) wasdissolved in anhydrous ether (30 mL). Iodotrimethylsilane (1.24 mL, 8.74mmol) was added and the solution was stirred for 1 h. The solution waspassed through a filter and the filtrate was concentrated under vacuumto yield the product as a yellow oil. ¹H NMR (400 MHz, C₆D₆) δ 7.35-6.69(m, 10H), 3.61 (s, 2H), 2.10 (b, J=6.6 Hz, 2H), 1.89 (s, 2H), ¹³C NMR(101 MHz, C₆D₆) δ 128.44 (d, J=1.4 Hz), 127.41, 127.35, 126.48 (d, J=2.6Hz), 51.47, 34.70. ³¹P NMR (162 MHz, C₆D₆) δ 111.51.

Step 2. Preparation ofrac-(2R,5R)—N-butyl-N-((2R,5R)-2,5-diphenylphospholan-1-yl)-2,5-diphenylphospholan-1-amine,L596

N-Butyl-2,5-diphenylphospholan-1-amine (0.68 g, 2.18 mol) is dissolvedin methylene chloride (35 mL) and triethylamine (0.61 mL, 4.37 mmol).(rac)-1-Iodo-2,5-diphenylphospholane (0.80 g, 0.2.18 mmol) was alsodissolved in methylene chloride (10 mL). The two solutions were chilledto −30° C. before being slowly combined. The sample was analyzed by ³¹PNMR spectroscopy which showed complete reaction to mostly one product.The reaction solution was concentrated to dryness under vacuum. Theresidue was slurried in hexane (40 mL) and was filtered. The solid wasrinsed with additional hexane (10 mL). The filtrate was concentrated to˜20 mL under vacuum whereupon a large amount of white solid precipitatedfrom the cold solution. The solid was collected by filtration and driedunder high vacuum. ¹H NMR (400 MHz, C₆D₆) δ 7.14 (m, 8H), 7.07-6.99 (m,8H), 6.95 (d, J=7.6 Hz, 4H), 3.25-3.00 (m, 4H), 2.58-2.38 (m, 2H),2.31-2.13 (m, 1H), 2.13-1.95 (m, 6H), 1.62-1.43 (m, 2H), 1.07-0.88 (m,1H), 0.68-0.51 (m, 2H), 0.48 (t, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 144.32(d, J=19.0 Hz), 140.86, 128.84-128.56 (m), 128.49, 126.04, 125.66, 52.78(t, J=11.8 Hz), 49.32 (d, J=21.0 Hz), 35.22-34.24 (m), 30.91 (t, J=4.4Hz), 20.16, 13.77. ³¹P NMR (162 MHz, C₆D₆) δ 91.12. HRMS (ESI-TOF) m/z:[M+H]+ Calcd for C₃₆H₄₁NP₂ 550.2787; Found 550.2797.

Preparation of(rac)-N-(di(furan-2-yl)phosphanyl)-N-isopropyl-2,5-diphenylphospholan-1-amine,L601 Step 1. Preparation of(rac)-N-isopropyl-2,5-diphenylphospholan-1-amine

A solution of (rac)-1-chloro-2,5-diphenylphospholane (0.80 g, 2.9 mmol)in hexanes (5 mL) was added to a solution of isopropylamine (2.5 mL, 29mmol) in hexanes (5 mL) resulting in immediate precipitation of a whitesolid. After stirring for 1 h, the mixture was checked by ³¹P NMRspectroscopy which showed complete conversion to a new product. Themixture was filtered and the volatiles removed under vacuum to yield theproduct as a yellow oil. Yield (0.81 g, 94%). ¹H NMR (400 MHz, C₆D₆) δ7.38-7.32 (m, 2H), 7.29-7.17 (m, 4H), 7.14-7.02 (m, 4H), 3.07 (ddd,J=22.2, 12.5, 6.0 Hz, 1H), 2.96-2.78 (m, 1H), 2.59 (m, 1H), 2.23-1.98(m, 2H), 1.79 (m, J=12.5, 5.1, 2.6 Hz, 1H), 1.58 (m, 1H), 1.00 (dd,J=10.6, 7.2 Hz, 1H), 0.80 (d, J=6.3 Hz, 3H), 0.46 (d, J=6.4 Hz, 3H), ¹³CNMR (101 MHz, C₆D₆) δ 144.42 (d, J=18.7 Hz), 140.39 (d, J=1.4 Hz),128.76, 128.45 (d, J=1.4 Hz), 128.41 (d, J=3.4 Hz), 127.96 (d, J=8.1Hz), 126.00 (d, J=2.6 Hz), 125.68 (d, J=1.9 Hz), 57.01 (d, J=14.8 Hz),50.20 (d, J=22.1 Hz), 49.12 (d, J=25.3 Hz), 34.09 (d, J=3.0 Hz), 31.83(d, J=2.1 Hz), 25.92 (dd, J=50.4, 5.8 Hz). ³¹P NMR (162 MHz, C₆D₆) δ67.37.

Step 2. Preparation of di(furan-2-yl)iodophosphine

Chlorodi (furan-2-yl) phosphine (2.0 mL, 13 mmol) was dissolved intoluene (10 mL). Iodotrimethylsilane (2.19 mL, 15.4 mmol) was added andthe orange solution was stirred at ambient temperature. After 2 h, thereaction was checked by ³¹P NMR spectroscopy which showed completeconversion to a new product. The solvent was removed under vacuum toyield the product as a red oil. Yield (3.5 g, 92%). ¹H NMR (400 MHz,C₆D₆) δ 7.27 (dd, J=1.8, 0.8 Hz, 2H), 6.73 (dt, J=3.5.0.9 Hz, 2H), 5.99(dd, J=3.5, 1.8 Hz, 2H), ¹³C NMR (101 MHz, C₆D₆) δ 149.03 (d, J=3.9 Hz),146.66 (d, J=37.9 Hz), 122.81 (d, J=28.1 Hz), 111.85 (d, J=5.5 Hz). ³¹PNMR (162 MHz, C₆D₆) δ −39.35.

Step 3. Preparation of(rac)-N-(di(furan-2-yl)phosphanyl)-N-isopropyl-2,5-diphenylphospholan-1-amine,L601

(rac)-N-isopropyl-2,5-diphenylphospholan-1-amine (0.30 g, 1.0 mmol) andtriethylamine (0.155 mL, 1.11 mmol) were dissolved in toluene (2 mL).Di(furan-2-yl)iodophosphine (0.315 g, 1.01 mmol) was also dissolved intoluene (2 mL). The two solutions were cooled in the freezer to −30° C.The di(furan-2-yl)iodophosphine solution was added dropwise to thesolution of (rac)-N-isopropyl-2,5-diphenylphospholan-1-amine andtriethylamine causing immediate formation of precipitate. The sample wasanalyzed by ³¹P NMR spectroscopy which showed complete conversion to theproduct. The solvent was removed. The residue was extracted with etherand passed through a short plug of alumina. The solvent was removed toyield the product as a white solid. Yield (0.36 g, 77%). ¹H NMR (400MHz, C₆D₆) δ 7.41-7.25 (m, 4H), 7.26-7.16 (m, 3H), 7.09-7.00 (m, 4H),7.00-6.90 (m, 1H); 6.42 (dd, J=3.3, 0.7 Hz, 1H), 6.09-5.98 (m, 2H), 5.95(dt, J=3.4, 1.8 Hz, 1H), 4.40-4.12 (m, 1H), 3.90-3.64 (m, 1H), 3.33(ddd, J=25.9, 13.2, 5.6 Hz, 1H), 3.15-2.90 (m, 1H), 2.53-2.34 (m, 1H),2.26-2.07 (m, 1H), 1.79-1.48 (m, 1H), 0.75 (dd J=25.9, 6.6 Hz, 6H). ¹³CNMR (101 MHz, C₆D₆) δ 146.28 (d, J=4.3 Hz), 146.03 (d, J=2.7 Hz), 144.41(d, J=20.9 Hz), 129.14 (t, J=3.0 Hz), 128.70 (d, J=1.3 Hz), 128.45 (d,J=8.1 Hz), 128.38 (d, J=1.2 Hz), 125.79 (dd, J=49.0, 2.3 Hz), 119.74 (d,J=26.2 Hz), 119.13 (d, J=16.4 Hz), 110.86 (d, J=2.7 Hz), 110.47 (d,J=5.7 Hz), 53.88 (dd, J=23.9, 6.9 Hz), 50.27 (dd, J=21.3, 4.8 Hz), 36.01(d, J=3.2 Hz), 33.23 (dd, J=8.1, 3.4 Hz), 24.05 (d, J=14.3 Hz), 23.61(d, J=11.7 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 75.57, 10.79 (d, J=38.6 Hz).HRMS (ESI-TOF) m/z: [M+H]+ Calcd for C₂₇H₂₉NO₂P₂ 462.1747; Found462.1730.

Preparation ofrac-N-butyl-N-(bis(4-fluorophenyl)phosphinyl-2,5-diphenylphospholan-1-amine,L603 Step 1. Preparation of bis(4-methylphenyl)iodophosphine

Iodotrimethylsilane (0.49 g, 2.5 mmol) was added to a solution ofbis(4-fluorophenyl)chlorophosphine (0.50 g, 1.9 mmol) in toluene (5.0mL) with rapid formation of orange color. The reaction mixture wasstirred at room temperature overnight, then filtered to remove the darkprecipitate which was suspended in the solution after the reaction. Thevolatiles were removed under vacuum and a yellowish liquid was obtained.Yield (0.52 g, 76%). ¹H NMR (400 MHz, C₅D₅CD₃) d 7.27 (m, 4H), 6.70-6.51(m, 4H), 33C NMR (101 MHz, C₆D₅CD₃) d 165.04 (d, J=1.0 Hz), 162.54,137.05, 135.54 (dd, J=24.9, 8.3 Hz), 130.85 (dd, J=38.9, 3.5 Hz), 115.57(dd, J=21.3, 7.1 Hz). ³¹P NMR (162 MHz, C₆D₅CD₃) d 36.68 (t, J=5.0 Hz).¹⁹F NMR (376 MHz, C₆D₆) δ −109.22-−109.69 (m).

Step 2. Preparation ofrac-N-butyl-N-(bis(4-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L603

A cold solution (−30° C.) of triethylamine (0.068 g, 0.67 mmol) intoluene-d₈ (1.4 mL) was added to a cold (−30° C.) solution ofrac-N-butyl-2,5-diphenylphospholan-1-amine (0.21 g, 0.67 mmol) intoluene-d₈ (2.1 mL) and the resulting mixture was stirred for 10 min.The mixture was placed in a freezer at −30° C. for 30 minutes. To thiscooled mixture was added a cold (−30° C.) solution of thebis(4-fluorophenyl)iodophosphine (0.23 g, 0.67 mmol) in toluene-dg (2.3mL) with formation of a white precipitate. The reaction mixture wasstirred for 30 min at ambient temperature. The volatiles were removedunder vacuum. The crude product was redissolved in toluene (10 mL). Thesolution was passed through a 5-cm plug of activated neutral alumina andthe solvent was evaporated under vacuum giving solid product which wasrecrystallized from cold pentane at −30° C. to produce the pure product.Yield 0.22 g (61%). ¹H NMR (400 MHz, C₆D₅CD₃) δ 7.33-7.26 (m, 2H),7.22-7.02 (m, 9H), 6.98 (t, J=7.3 Hz, 1H), 6.80-6.70 (m, 2H), 6.70-6.49(m, 4H), 3.87 (m, 1H), 3.24 (m, 1H), 3.04-2.72 (m, 2H), 2.47-2.27 (m,1H), 2.15 (m, 1H), 1.54 (ddt, J=12.8.4.6, 2.1 Hz, 1H), 1.02-0.81 (m,1H), 0.65 (m, 2H), 0.47 (t, J=7.1 Hz, 3H), ¹³C NMR (101 MHz, C₆D₅CD₃) δ143.83 (d, J=20.8 Hz), 139.02 (d, J=2.7 Hz), 137.05, 134.85 (d, J=7.9Hz), 134.63 (d, J=7.8 Hz), 134.09 (d, J=7.7 Hz), 133.87 (d, 7.8 Hz),128.32, 128.27, 128.12, 125.83 (d, J=2.5 Hz), 125.39 (d, J=1.9 Hz),115.28 (d, J=6.0 Hz), 115.07 (d, J=6.0 Hz), 114.56 (d, J=6.6 Hz), 53.83(d, J=28.7 Hz), 51.29 (d, J=19.9 Hz), 36.45, 33.65 (d, J=5.4 Hz), 32.79,13.38. ³¹P NMR (162 MHz, C₆D₅CD₃) δ 98.19 (d, J=22.4 Hz), 58.38-54.20(m). ¹⁹F NMR (376 MHz, C₆D₅CD₃) δ −112.24-−112.40 (m), −112.71 (m).

Preparation of(2S,5S)—N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine.Ligand 604 Step 1. Preparation ofbis(2-fluorophenyl)dimethylaminophosphine

1-Bromo-2-fluorobenzene (18.50 g, 105.7 mmol) was added slowly dropwiseto a chilled (−85 to −80° C. (liquid nitrogen/acetone bath)) solution ofn-butyllithium (42.0 mL, 2.38 M, 99.9 mmol) in ether (200 mL) such thatthe temperature did not exceed −78° C. The temperature was allowed toincrease to between −78 and −75° C. for one hour with formation of whiteprecipitate. The reaction mixture was cooled to −85° C. A solution ofdimethylphosphoramidous dichloride (7.295 g, 49.98 mmol) in ether (10mL) was added very slowly dropwise such that the temperature did notexceed −80° C. Dry ice was added to the bath and the reaction mixturewas allowed to stir overnight while warming to ambient temperature. ³¹Pand ¹⁹F NMR spectra showed the product to be about 99.5% desiredproduct. The reaction mixture was filtered and the volatiles wereremoved under reduced pressure. The residue was extracted with hexane,filtered, and the volatiles were removed under reduced pressure to givethe product as a pale yellow oil, 12.72 g, 95.95%. ¹H NMR (400 MHz,CDCl₃) δ 7.34 (ddddd, J=8.3, 7.3, 5.5, 1.9, 1.0 Hz, 1H), 7.23 (tddd,J=5.6, 4.6, 2.4, 1.3 Hz, 1H), 7.15 (tt, J=7.5.1.0 Hz, 1H), 7.05 (dddd,J=9.4, 8.2, 4.1, 1.1 Hz, 1H), ¹³C NMR (101 MHz, CDCl₃) δ 163.47 (dd,J=244.5, 16.1 Hz), 132.23 (t, J=5.9 Hz), 130.65 (d, J=8.2 Hz), 124.85(td, J=20.2, 2.0 Hz), 124.17 (d, J=3.4 Hz), 115.10 (d, J=23.3 Hz). ³¹PNMR (162 MHz, CDCl₃) δ 44.59 (t, J=45.7 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ−105.77 (ddt, J=45.6, 11.6, 6.2 Hz).

Steps 2 and 3. Preparation of bis(2-fluorophenyl)chlorophosphine andbis(2-fluorophenyl)iodophosphine

Iodotrimethylsilane (TMSI) (7.11 g, 34.5 mmol) was added to a solutionof bis(2-fluorophenyl)dimethylaminophosphine (8.100 g, 30.54 mmol) inhexane (40 mL). ³¹P and ¹⁹F NMR spectra taken immediately after mixingshowed slight (a few ppm) chemical shifts from the starting material.The reaction mixture was stirred over several days. An aliquot wasremoved and devolatilized: The NMR spectra showed that no reaction hadtaken place. HCl solution (35 mL, 2.0 M, 70 mmol) was added withformation of copious precipitate. NMR spectra showed that the startingmaterial was all consumed. The reaction mixture was filtered. NMRspectra showed only bis(2-fluorophenyl)chlorophosphine, but not anybis(2-fluorophenyl)iodophosphine. The volatiles were removed underreduced pressure, the residue was dissolved in ether andiodotrimethylsilane (7.00 g, 34.98 mmol) was added. After stirring forseveral hours, the volatiles were removed under reduced pressure. Theresidue was extracted with hexane, filtered, and the volatiles wereremoved under reduced pressure to give bis(2-fluorophenyl)iodophosphineas a yellow-orange oil. Yield was 10.17 g, 95.65%. NMR spectra forbis(2-fluorophenyl)chlorophosphine: ¹H NMR (400 MHz, CDCl₃) δ 7.57 (tdd,J=7.5, 5.6, 1.7 Hz, 1H), 7.44 (ddddd, J=8.0, 7.2, 5.3, 1.8, 0.6 Hz, 1H),7.22 (tt, J=7.6, 0.9 Hz, 1H), 7.06 (dddd, J=9.5, 8.3, 4.4, 1.1 Hz, 1H),¹³C NMR (101 MHz, CDCl₃) δ 163.57 (dd, J=247.9, 19.0 Hz), 132.96 (d,J=8.9 Hz), 132.83 (tdd, J=10.2, 3.2, 1.3 Hz), 124.69 (dt, J=3.3, 1.5Hz), 124.50-123.86 (m), 115.51 (d, J=23.0 Hz). ³¹P NMR (162 MHz, CDCl₃)δ 61.33 (t, J=64.9 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −105.22 (dm, J=65.5Hz). NMR spectra for bis(2-fluorophenyl)iodophosphine: ¹H NMR (400 MHz,CDCl₃) δ 7.59 (tdd, J=7.4, 5.0, 1.7 Hz, 1H), 7.44 (ddddd, J=8.1, 7.3,5.4, 1.8, 0.8 Hz, 1H), 7.19 (tt, J=7.5, 1.0 Hz, 1H), 7.06 (dddd, J=9.5,8.2, 4.4, 1.1 Hz, 1H), ¹³C NMR (101 MHz, CDCl₃) δ 163.31 (dd, J=248.2,18.8 Hz), 136.30 (dd, J=8.8, 3.1 Hz), 133.08 (d, J=8.6 Hz),124.87-124.72 (m), 120.54 (ddd, J=45.4, 17.1, 1.9 Hz), 115.46 (d, J=22.8Hz). ³¹P NMR (162 MHz, CDCl₃) δ 11.95 (t, J=63.7 Hz). ¹⁹F NMR (376 MHz,CDCl₃) δ −101.52 (ddt, J=63.5, 9.5, 6.2 Hz).

Step 4. Preparation of(2S,5S)—N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,Ligand 604

A solution of bis(2-fluorophenyl)iodophosphine (0.229, 0.660 mmol) inCDCl₃ (2 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.205 g, 0.66 mmol) andtriethylamine (0.500 g, 4.94 mmol) in CDCl₃ (5 mL). The solvents wereremoved under reduced pressure to give a solid. The residue wasextracted with hexane and ether and filtered and the volatiles wereremoved under reduced pressure. The solids were washed with hexane anddried under reduced pressure to give the product as a colorless solid.¹H NMR (400 MHz, C₆D₆) δ 7.43 (dt, J=8.0, 1.5 Hz, 2H), 7.36 (dt, J=7.1,1.6 Hz, 2H), 7.24 (t, J=7.8 Hz, 2H), 7.09 (tq, J=7.3, 1.3 Hz; 1H), 7.04(ddd, J=5.9, 4.1, 1.7 Hz, 1H), 6.99 (dd, J=8.3, 6.9 Hz, 2H), 6.91-6.79(m, 3H), 6.73 (dddd, J=9.6, 8.2, 4.2, 1.2 Hz, 1H), 6.70-6.63 (m, 3H),6.60 (td, J=7.4, 1.2 Hz, 1H), 4.40 (ddt, J=12.3, 8.4, 4.6 Hz, 1H),3.36-3.16 (m, 1H), 3.16-2.94 (m, 3H), 2.66-2.48 (m, 1H), 2.10 (tt,J=10.5, 5.2 Hz, 1H), 1.59 (qd, J=12.6, 5.0 Hz, 1H), 1.08-0.94 (m, 1H),0.70-0.45 (m, 3H), 0.36 (t, J=7.2 Hz, 3H), ¹³C NMR (101 MHz, C₆D₆) δ164.56 (dd, J=245.2, 18.7 Hz), 162.79 (dd, J=244.5, 16.6 Hz), 144.84 (d,J=21.1 Hz), 139.02 (d, J=1.9 Hz), 133.54 (dd, J=7.4, 5.1 Hz), 133.38 (t,J=4.8 Hz), 131.62 (d, J=8.5 Hz), 130.01 (d, J=8.1 Hz), 128.83 (dd,J=3.9, 1.9 Hz), 128.73, 128.63, 128.35 (d, J=1.1 Hz), 126.60 (ddd,J=27.1, 18.7, 1.6 Hz), 125.96 (ddd, J=23.1, 18.6, 2.4 Hz), 125.95 (dd,J=15.9, 2.3 Hz), 124.39 (d, J=3.1 Hz), 124.26 (d, J=3.3 Hz), 115.51 (d,J=23.9 Hz), 114.79 (d, J=23.1 Hz), 55.31 (td, J=9.1, 3.1 Hz), 55.00 (d,J=3.5 Hz), 52.62 (dd, J=22.4, 4.4 Hz), 37.04, 34.14 (d, J=7.3 Hz), 32.81(dd, J=8.6, 3.5 Hz), 19.91, 13.64. ³¹P NMR (162 MHz, C₆D₆) δ 103.28 (d,J=28.9 Hz), 32.93 (ddd, J=54.9, 42.6, 28.7 Hz). ¹⁹F NMR (376 MHz, C₆D₆)δ −103.52 (din, J=41.8 Hz), −104.72 (dm, J=54.7 Hz). HRMS: Expected(M+1): 532.2128. Found (M+1): 532.2137.

Preparation of(rac)-N-(diphenylphosphanyl)-N-ethyl-2,5-diphenylphospholan-1-amine,L606 Step 1. Preparation of (rac)-N-ethyl-2,5-diphenylphospholan-1-amine

A solution of (rac)-1-chloro-2,5-diphenylphospholane (0.40 g, 1.5 mmol)in hexanes (5.0 mL) was added to a solution of ethylamine (2 M) in THF(3.6 mL, 7.3 mmol), resulting in immediate precipitation of a whitesolid. After stirring overnight, the volatiles were removed undervacuum. The residue was slurried with hexanes and filtered. Thevolatiles were removed under vacuum to yield the product as a yellowoil. Yield (0.40, 96%). ¹H NMR (400 MHz, C₆D₆) δ 7.32-7.24 (m, 2H),7.23-6.97 (m, 8H), 2.99 (ddd, J=21.7, 12.6, 6.0 Hz, 1H), 2.91-2.78 (m,1H), 2.48-2.29 (m, 1H), 2.28-1.92 (m, 3H), 1.87-1.65 (m, 1H), 1.63-1.40(m, 1H), 0.90 (q, J=7.0 Hz, 1H), 0.46 (t, J=7.1 Hz, 3H), ¹³C NMR (101MHz, C₆D₆) δ 144.08, 143.89, 139.83, 128.34, 128.06 (d, J=1.4 Hz),127.75 (d, J=11.7 Hz), 125.60 (d, J=2.6 Hz), 125.22 (d, J=1.9 Hz), 55.43(d, J=14.1 Hz), 50.08 (d, J=23.2 Hz), 42.11 (d, J=23.7 Hz), 33.97 (d,J=2.6 Hz), 31.33 (d, J=2.1 Hz), 18.10 (d, J=7.2 Hz). ³¹P NMR (162 MHz,C₆D₆) δ 72.81.

Step 2. Preparation of(rac)-N-(diphenylphosphanyl)-N-ethyl-2,5-diphenylphospholan-1-amine,L606

(rac)-N-Ethyl-2,5-diphenylphospholan-1-amine (0.15 g, 0.53 mmol) andtriethylamine (81 uL, 0.58 mmol) were dissolved in toluene (5.0 mL).Iododiphenylphosphine (0.17 g, 0.53 mmol) was also dissolved in toluene(5 mL). The two solutions were cooled in the freezer to −30° C. Theiododiphenylphosphine solution was added dropwise to the solution of(rac)-N-ethyl-2,5-diphenylphospholan-1-amine and triethylamine causingimmediate formation of precipitate. After stirring at ambienttemperature for 30 minutes, the volatiles were removed under vacuum. Theresidue was extracted with ether and the mixture was filtered through aplug of activated neutral alumina. The solvent was removed under vacuumto yield the final product. Yield (0.19 g, 77%). ¹H NMR (400 MHz, C₆D₆)δ 7.43-7.28 (m, 4H), 7.28-7.13 (m, 4H), 7.13-6.86 (m, 10H), 6.85-6.70(m, 2H), 4.01 (ddt, J=12.1, 7.5, 4.5 Hz, 1H), 3.49-3.19 (m, 1H),3.10-2.79 (m, 3H), 2.53-2.24 (m, 1H), 2.13 (tt, J=10.7, 5.3 Hz, 1H),1.73-1.39 (m, 1H), 0.45-0.27 (m, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 144.28(d, J=21.0 Hz), 140.54 (d, J=22.2 Hz), 139.18 (d, J=2.5 Hz), 138.61 (d,J=16.4 Hz), 132.91 (d, J=20.0 Hz), 132.10 (d, J=20.3 Hz), 128.77 (dd,J=3.6, 1.8 Hz), 128.38, 128.34, 128.21, 128.12 (d, J=5.6 Hz), 128.03,127.59, 125.73 (d, J=2.6 Hz), 125.35 (d, J=1.9 Hz), 55.15 (dd, J=21.9,18.4 Hz), 51.53 (dd, J=22.8, 3.4 Hz), 48.71 (dd, J=32.0, 4.2 Hz), 36.44(d, J=2.7 Hz), 32.83 (dd, J=7.5, 3.3 Hz), 16.64 (d, J=7.3 Hz). ³¹P NMR(162 MHz, C₆D₆) δ 97.75 (d, J=19.7 Hz), 58.57 (d, J=19.9 Hz). HRMS(ESI-TOF) m/z: [M+H]+ Calcd for C₃₀H₃₁NP₂ 468.2005; Found 468.1999.

Preparation of(rac)-N-butyl-N-(bis([1,1′:3′,1″-terphenyl]-5′-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L607 Step 1. Preparation of bis(3,5-diphenylphenyl)iodophosphine

Iodotrimethylsilane (0.16 mL, 1.1 mmol) was added to a solution ofbis(3,5-diphenylphenyl)chlorophosphine (0.50 g, 0.95 mmol) in toluene(2.0 mL). After 2 h stirring at ambient temperature, the orange solutionwas filtered and the volatiles were removed to yield a yellow solid. Theproduct was washed with pentane, filtered, and dried under reducedpressure. The crude product was used as-is in the next step. Yield (0.45g, 59%). ¹H NMR (400 MHz, Benzene-d₆) δ 8.13 (dd, J=7.7, 1.7 Hz, 3H),7.68-7.55 (m, 3H), 7.40-7.28 (m, 7H), 7.25-6.89 (m, 13H). ³¹P NMR (162MHz, C₆D₆) δ 39.07.

Step 2. Preparation of(rac)-N-butyl-N-(bis([1,1′:3′,1″-terphenyl]-5′-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L607

(rac)-N-Butyl-2,5-diphenylphospholan-1-amine (0.15 g, 0.48 mmol) andtriethylamine (0.74 uL, 0.53 mmol) were dissolved in toluene (5.0 mL).Bis(3,5-diphenylphenyl)iodophosphine (0.30 g, 0.48 mmol) was alsodissolved in toluene (5.0 mL). The two solutions were cooled in thefreezer to −30° C. The bis(3,5-diphenylphenyl)iodophosphine solution wasadded dropwise to the solution of(rac)-N-butyl-2,5-diphenylphospholan-1-amine (0.15 g, 0.48 mmol) andtriethylamine causing immediate formation of precipitate. The volatileswere removed under vacuum and the residue was extracted with ether. Themixture was filtered through a plug of neutral activated alumina. Theether was removed under vacuum to yield a white solid. The solid wastriturated with pentane and dried to yield the pure product as a whitesolid. Yield (0.2 g, 52%). ¹H NMR (400 MHz, C₆D₆) δ 7.91 (dd, J=6.5, 1.7Hz, 2H), 7.81-7.71 (m, 1H), 7.70-7.59 (m, 1H), 7.48 (dd, J=7.2, 1.8 Hz,4H), 7.46-7.34 (m, 8H), 7.32-7.24 (m, 2H), 7.21-6.89 (m, 17H), 6.63 (t,J=7.4 Hz, 1H), 4.31 (ddt, J=12.3, 7.4, 4.7 Hz, 1H), 3.49-3.07 (m, 4H),2.57-2.29 (m, 1H), 2.31-2.05 (m, 1H), 1.74-1.35 (m, 1H), 1.22-0.97 (m,1H), 0.67-0.43 (m, 2H), 0.35 (t, J=7.2 Hz, 3H). ¹³C NMR (101 MHz, C₆D₆)δ 144.46 (d, J=21.3 Hz), 142.51 (d, J=5.3 Hz), 142.10 (d, J=6.1 Hz),141.33 (d, J=20.0 Hz), 140.22 (d, J=19.0 Hz), 139.07 (d, J=2.2 Hz),131.41 (d, J=21.0 Hz), 130.01 (d, J=20.2 Hz), 129.09 (d, J=15.6 Hz),128.85, 128.78, 128.53, 127.71 (d, J=8.0 Hz), 127.63, 127.21 (d, J=25.6Hz), 126.15 (dd, J=5.5, 2.1 Hz), 56.05 (dd, J=21.8, 19.9 Hz), 55.37 (d,J=6.7 Hz), 55.04 (d, J=6.8 Hz), 52.66 (dd, J=22.6, 3.2 Hz), 37.19, 34.51(d, J=7.6 Hz), 33.57 (d, J=5.7 Hz), 19.99, 13.90. ³¹P NMR (162 MHz,C₆D₆) δ 98.25 (d, J=24.2 Hz), 59.04 (d, J=24.6 Hz). HRMS (ESI-TOF) m/z:[M+H]+ Calcd for C₅₆H₅₁NP₂ 800.3570; Found 800.3557.

Preparation ofrac-N-cyclopropyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L608 Step 1. Preparation ofrac-N-cyclopropyl-2,5-diphenylphospholan-1-amine

A solution of cyclopropylamine (0.43 mL, 6.6 mmol) in hexanes (5.00 mL)was added to a solution of rac-1-chloro-2,5-diphenyl-phospholane (0.60g, 2.2 mmol) in hexane (5.00 mL). The mixture was stirred at roomtemperature overnight. The solids were removed by filtration using adisposable filter funnel and the solution was passed through a 5-cm plugof activated neutral alumina. Solvent was evaporated under vacuum toproduce a white solid. Yield 0.27 g (41.5%). ¹H NMR (400 MHz, C₆D₅CD₃) δ7.24 (dt, J=8.0, 1.6 Hz, 2H), 7.17 (td, J=7.3, 1.7 Hz, 4H), 7.13-7.08(m, 2H), 7.08-7.00 (m, 2H), 2.96 (ddd, J=22.2, 12.6, 5.9 Hz, 1H), 2.78(ddd, J=12.4, 7.3, 5.7 Hz, 1H), 2.13 (ddddd, J=14.4, 12.6, 7.2, 5.1, 1.5Hz, 1H), 2.07-1.97 (m, 1H), 1.75 (qdd, J=12.5, 5.1, 2.4 Hz, 1H),1.62-1.44 (m, 3H), 0.11-0.00 (m, 3H), −0.06 (tdt, J=6.3, 3.5, 2.4 Hz,1H). ¹³C NMR (101 MHz, C₆D₅CD₃) δ 143.88 (d, J=19.1 Hz), 139.70, 128.28(d, J=1.1 Hz), 128.03 (d, J=1.2 Hz), 127.83 (d, J=3.4 Hz), 127.55,127.46, 125.55 (d, J=2.5 Hz), 125.28 (d, J=1.9 Hz), 55.11 (d, J=14.2Hz), 50.16 (d, J=24.0 Hz), 34.12 (d, J=1.9 Hz), 31.18 (d, J=2.3 Hz),27.50 (d, J=22.3 Hz), 9.22 (d, J=11.6 Hz), 8.05 (d, J=8.0 Hz). ³¹P NMR(162 MHz, C₆D₅CD₃) δ 67.73.

Step 2. Preparation ofrac-N-cyclopropyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L608

A cold solution (−30° C.) of triethylamine (0.034 g, 0.34 mmol) intoluene-ds (0.69 mL) was added to a cold (−30° C.) solution ofrac-N-cyclopropyl-2,5-diphenylphospholan-1-amine (2) (0.10 g, 0.34 mmol)in toluene-ds (1.00 mL) and the resulting reaction mixture was stirredfor 10 min. The reaction mixture was placed in a freezer at −30° C. for30 minutes. To this cooled reaction mixture was added a cold (−30° C.)solution of iododiphenylphosphine (0.11 g, 0.34 mmol) in 1.06 mL oftoluene-d₈ with formation of a white precipitate. The reaction mixturewas stirred for 30 min at ambient temperature. Solvent was removed undervacuum. The crude product was redissolved in a diethyl ether and toluene(50/50 v/v) solvent mixture (5 mL) and filtered through a 5-cm plug ofactivated neutral alumina and the solvent was evaporated under vacuumgiving solid product which was recrystallized from cold pentane at −30°C. to produce pure product. Yield 0.059 g (36.3%). ¹H NMR (400 MHz,C₆D₆) δ 7.39-7.28 (m, 4H), 7.23 (dt, J=8.1, 1.5 Hz, 2H), 7.17 (dd,J=8.5, 6.8 Hz, 2H), 7.12-6.91 (m, 12H), 4.13 (dddd, J=11.5, 7.7, 6.0,3.3 Hz, 1H), 3.38-3.10 (m, 1H), 3.07-2.86 (m, 1H), 2.36 (ddddd, j=14.1,12.8, 7.7, 5.0, 1.2 Hz, 1H), 2.23-1.93 (m, 2H), 1.66-1.39 (m, 1H),0.68-0.44 (m, III), 0.13-−0.09 (m, 1H), −0.13-−0.42 (m, 2H), ¹³C NMR(101 MHz, C₆D₆) δ 144.56 (d, J=22.6 Hz), 140.01 (d, J=21.1 Hz), 139.48(d, J=1.8 Hz), 137.10 (dd, J=17.5, 1.5 Hz), 135.04 (d, J=22.5 Hz),131.25 (d, J=18.3 Hz), 128.72, 128.63, 128.53, 128.49 (d, J=1.4 Hz),128.33, 128.17, 127.95, 127.72, 127.32, 125.77 (d, J=2.5 Hz), 125.33 (d,J=1.8 Hz), 53.70 (t, J=22.2 Hz), 52.18 (dd, J=25.6, 2.5 Hz), 37.28 (d,J=2.3 Hz), 35.18 (dd, J=27.8, 6.3 Hz), 33.04 (dd, J=7.5, 2.9 Hz), 9.21(d, J=12.6 Hz), 8.42 (d, J=21.1 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 95.14 (d,J=16.2 Hz), 61.52 (d, J=16.2 Hz).

Preparation ofrac-N-cyclobutyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L613 Step 1. Preparation ofrac-N-cyclobutyl-2,5-diphenylphospholan-1-amine

A solution of cyclobutylamine (0.54 mL, 6.6 mmol) in hexanes (5.00 mL)was added to a solution of rac-1-chloro-2,5-diphenyl-phospholane (0.60g, 2.2 mmol) in hexanes (5.00 mL). The reaction mixture was stilted atroom temperature overnight. The reaction mixture was filtered through adisposable filter funnel and then through a 5-cm plug of activatedneutral alumina. Solvent was evaporated under vacuum to give a whitesolid. Yield 0.40 g (58.8%). ¹H NMR (400 MHz, C₆D₆) δ 7.25 (dt, J=8.0,1.7 Hz, 2H), 7.15 (qd, J=7.5, 1.6 Hz, 4H), 7.09-6.94 (m, 4H), 3.09-2.89(m, 2H), 2.89-2.78 (m, 1H), 2.12 (dddd, J=20.3, 11.0, 7.1, 5.3 Hz, 1H),2.06-1.93 (m, 1H), 1.77 (dddd, J=19.7, 9.3, 4.8, 2.1 Hz, 2H), 1.61-1.43(m, 1H), 1.42-1.24 (m, 3H), 1.14 (qd, J=9.6, 9.0, 4.9 Hz, 1H), 1.08-0.78(m, 2H), ¹³C NMR (101 MHz, C₆D₆) δ 143.96 (d, J=18.7 Hz), 139.79,127.92, 127.65, 127.62, 127.54, 127.41, 125.60 (d, J=2.4 Hz), 125.24 (d,J=1.9 Hz), 55.71 (d, J=14.1 Hz), 53.95 (d, J=22.7 Hz), 50.00 (d, J=22.9Hz), 34.30 (d, J=3.4 Hz), 34.20 (d, J=7.9 Hz), 33.89 (d, J=2.4 Hz),31.32 (d, J=2.3 Hz), 13.49. ³¹P NMR (162 MHz, C₆D₆) δ 69.19.

Step 2. Preparation ofrac-N-cyclobutyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L613

A cold solution (−30° C.) of triethylamine (0.049 g, 0.48 mmol) intoluene-ds (0.98 mL) was added to a cold (−30° C.) solution ofrac-N-cyclobutyl-2,5-diphenylphospholan-1-amine (3) (0.15 g, 0.48 mmol)in toluene-ds (1.50 mL). The resulting mixture was stirred for 10 min,then was placed in a freezer at −30° C. for 30 minutes. To this cooledmixture was added a cold (−30° C.) solution of iododiphenylphosphine(0.15 g, 0.48 mmol) in toluene-ds (1.51 mL) with formation of a whiteprecipitate. The reaction mixture was stirred for 30 min at ambienttemperature. Solvent was removed under vacuum. The crude product wasextracted with a diethyl ether and toluene (50/50 v/v) solvent mixture(5 mL) and filtered through a 5-cm plug of activated neutral alumina.The solvent was evaporated under vacuum giving solid material which wasrecrystallized from cold pentane at −30° C. to produce pure product.Yield 0.19 g (79.4%). ¹H NMR (400 MHz, C₆D₆) δ 7.41 (td, J=7.0, 3.4 Hz,2H), 7.30 (d, J=7.6 Hz, 2H), 7.34 (dq, J=39.9, 5.9, 4.8 Hz, 4H),7.09-6.87 (m, 3 OH), 6.63 (q, J=6.2 Hz, 2H), 4.05 (tt, J=8.0, 4.0 Hz,1H), 3.62 (dq, J=16.2, 8.7, 8.1 Hz, 1H), 3.36 (ddd, J=25.9, 13.1, 4.9Hz, 1H), 3.00 (d, J=13.2 Hz, 1H), 2.37 (dt, J=23.9, 13.9 Hz, 2H), 2.11(dtd, J=17.9, 10.1, 4.6 Hz, 2H), 1.73-1.43 (m, 3H), 1.32 (d, J=10.4 Hz,1H), 1.01 (t, J=10.0 Hz, 1H), ¹³C NMR (101 MHz, C₆D₆) δ 143.78 (d,J=21.0 Hz), 140.85 (d, J=24.2 Hz), 139.11-138.57 (m), 132.32 (d, J=21.8Hz), 131.81 (d, J=18.9 Hz), 128.66 (t, J=2.7 Hz), 128.42, 128.20,128.12, 128.07, 128.01, 127.92, 127.47, 125.59 (d, J=2.6 Hz), 125.23 (d,J=1.9 Hz), 57.37 (d, J=25.4 Hz), 55.28-53.43 (m), 50.15 (d, J=21.8 Hz),35.69 (d, J=3.5 Hz), 33.26 (d, J=13.4 Hz), 33.00-32.76 (m), 32.52 (d,J=12.5 Hz), 14.41. ³¹P NMR (162 MHz, C₆D₆, 60° C.) δ 77.62, 59.27. HRMS:Expected (M+1): 494.216; Found (M+1): 494.2169

Preparation of2S,5S)—N-(bis(3,4,5-trifluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L615 Step 1. Preparation ofbis(3,4,5-trifluorophenyl)dimethylaminophosphine

5-Bromo-1,2,3-trifluorobenzene (19.855 g, 94.110 mmol) was added slowlydropwise to a chilled (−85 to −80° C. (liquid nitrogen/acetone))solution of n-butyllithium (9.10 mL, 2.38 M, 21.7 mmol combined with45.5 mL, 1.57 M, 71.4 mmol; total: 93.1 mmol) in ether (200 mL) suchthat the temperature did not exceed −89° C. The temperature was allowedto increase to between −78 and −75° C. for 2.5 hours (dry ice bath) withformation of white precipitate. The reaction mixture was cooled to −85°C. A solution of dimethylphosphoramidous dichloride (6.791 g, 46.53mmol) in ether (10 mL) was added very slowly dropwise such that thetemperature did not exceed −80° C. Dry ice was added to the bath and thereaction mixture was allowed to stir overnight while warming to ambienttemperature. ³¹P and ¹⁹F NMR spectra showed the product to be about99.5% desired product. The reaction mixture was filtered and thevolatiles were removed under reduced pressure. The residue was extractedwith hexane, filtered, and the volatiles were removed under reducedpressure to give 5 as a pale yellow oil, 13.50 g, 86.04%. ¹H NMR (500MHz, CDCl₃) δ 6.95 (dt, J=7.5, 6.4 Hz, 4H), 2.64 (d, J=9.7 Hz, 6H). BCNMR (101 MHz, CDCl₃) δ 151.35 (dddd, J=254.1, 10.0, 8.2, 3.0 Hz), 140.00(dtd, J=254.5, 15.5, 2.2 Hz), 134.44 (dq, J=21.9, 3.7 Hz), 115.41 (ddd,J=21.7, 15.1, 5.5 Hz), 41.47 (d, J=16.3 Hz). ³¹P NMR (202 MHz, CDCl₃) δ65.05. ¹⁹F NMR (376 MHz, CDCl₃) δ −133.39-−133.55 (m), −159.17 (ttd,J=20.3, 6.7, 3.4 Hz).

Step 2. Preparation of bis(3,4,5-trifluorophenyl)chlorophosphine

Anhydrous HCl in ether (55.0 mL, 2.0 M, 110 mmol) was added to a chilled(−35 to −30° C.) solution ofbis(3,4,5-trifluorophenyl)dimethylaminophosphine (13.30 g, 39.44 mmol)in methylene chloride (125 mL) (in two portions—NMR spectra after thefirst portion showed the reaction was incomplete) with formation of someprecipitate. The reaction mixture was stirred for two hours. NMR spectraafter the second portion showed the reaction was complete. Hexane (100mL) was added and the reaction mixture was filtered. The volatiles wereremoved under reduced pressure to give an oil containing precipitate.The residue was extracted with hexane and filtered. The volatiles wereremoved under reduced pressure to give clear yellow oil, 12.74 g, 98.3%.¹H NMR (400 MHz, CDCl₃) δ 7.19 (dtd, J=7.1, 6.3, 1.0 Hz, 1H). ¹³C NMR(101 MHz, CDCl₃) δ 151.45 (dtd, J=256.3, 10.1, 3.1 Hz), 141.38 (dtd,J=258.1, 15.2, 2.0 Hz), 133.93 (dq, J=37.9, 4.8 Hz), 115.64 (ddd,J=26.9, 15.6, 6.2 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 74.93 (t, J=3.1 Hz).¹⁹F NMR (376 MHz, CDCl₃) δ −131.41 (dd, J=20.2, 6.7 Hz), −155.11 (ttd,J=20.0, 6.5, 3.0 Hz).

Step 3 Preparation of bis(3,4,5-triflourophenyl)iodophosphine

Iodotrimethylsilane (TMSI) (9.960 g, 49.78 mmol) is added quicklydropwise to a solution of bis(3,4,5-trifluorophenyl)chlorophosphine(12.50 g 38.04 mmol) in toluene to give a yellow solution. The reactionmixture was stirred overnight. The volatiles were removed under reducedpressure to give the product as yellow oil. Addition of hexane causedprecipitation to occur, however the precipitate appeared to be less thanabout one or two grams in amount. The hexane mother liquor was veryyellow, indicating the presence of much dissolved product. The volatileswere removed under reduced pressure to give the product as yellow oilwhich is a mixture of bis(3,4,5-trifluorophenyl)iodophosphine (94%) anddiiodo(3,4,5-trifluorophenyl)phosphine (6%). The yield was 13.006 g,81.39%. ¹H NMR (400 MHz, CDCl₃) δ 7.28 (pseudo quartet, J=7.2 Hz, 4H),¹³C NMR (101 MHz, CDCl₃) δ 151.10 (dddd, J=256.3, 10.3, 9.2, 3.3 Hz),141.09 (dtd, J=258.4, 15.2, 2.3 Hz), 130.29 (dq, J=43.0, 4.8 Hz), 117.75(ddd, J=25.5, 15.5, 6.1 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 30.25 (t, J=3.1Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −131.52 (dd, J=20.3, 6.8 Hz), −155.14(ttd, J=20.0, 6.3, 2.9 Hz).

Step 4. Preparation of(2S,5S)—N-(bis(3,4,5-trifluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L615

A solution of bis(3,4,5-trifluorophenyl)iodophosphine (0.302 g, 0.720mmol) in ether (5 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.224 g, 0.72 mmol) andtriethylamine (0.728 g, 7.19 mmol) in ether (5 mL). Once about 80% ofthe bis(3,4,5-trifluorophenyl)iodophosphine had been added, NMR spectrawere taken which showed excess phospholane was present. Additionalbis(3,4,5-trifluorophenyl)iodophosphine was added. NMR spectra showedthe reaction was still incomplete. The remainingbis(3,4,5-trifluorophenyl)iodophosphine was added and the mixture wasallowed to stir overnight. The reaction mixture was filtered and thevolatiles were removed under reduced pressure. The residue wasrecrystallized twice from hexane and dried under reduced pressure togive the product as a colorless powder, 0.1322 g, 30.5%. NMR (400 MHz,CDCl₃) δ 7.68-7.48 (m, 10H), 7.17 (qd, J=6.3, 1.1 Hz, 2H), 6.57 (dt,J=7.5, 6.4 Hz, 2H), 4.00 (ddt, J=12.7, 7.6, 3.9 Hz, 1H), 3.87 (ddd,J=25.1, 13.2, 5.9 Hz, 1H), 3.34-3.18 (m, 1H), 3.18-3.05 (m, 1H),2.94-2.81 (m, 1H), 2.74 (tt, J=11.0, 5.3 Hz, 1H), 2.10 (dtdd, J=13.2,11.1, 5.2, 2.6 Hz, 1H), 1.66-1.55 (m, 1H), 1.30-1.09 (m, 3H), 1.02-0.92(m, 1H), 0.90 (t, J=7.2 Hz, 3H), 13C NMR (126 MHz, CDCl₃) δ 151.15(dddd, J=255.0, 10.5, 8.4, 2.9 Hz), 150.71 (dddd, J=253.6, 18.5, 8.8,3.0 Hz), 142.64 (d, J=20.2 Hz), 140.97 (dtd, J=40.1, 15.4, 2.1 Hz),138.94 (dtd, J=39.4, 15.4, 2.3 Hz), 138.17 (d, J=2.9 Hz), 135.56 (d,J=28.1 Hz), 133.97 (dq, J=21.5, 4.1 Hz), 128.65, 128.55-128.42 (m),127.88 (d, J=9.0 Hz), 126.24 (d, J=2.4 Hz), 126.18 (d, J=1.9 Hz),116.05, 115.93 (dddd, J=27.5, 21.5, 15.8, 4.9 Hz), 55.54 (dd, J=22.1,14.1 Hz), 54.11 (d, J=24.0 Hz), 50.87 (dd, J=22.5, 4.2 Hz), 36.27 (d,J=3.7 Hz), 33.69 (dd, J=5.9, 2.5 Hz), 32.92 (dd, J=6.0, 3.2 Hz), 19.66,13.50. ³¹P NMR (162 MHz, CDCl₃) δ 98.98 (d, J=15.9 Hz), 58.18 (d, J=15.7Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −132.78 (m), −133.64 (m), −157.93 (m),−159.15 (m). HRMS: Expected (M+1): 604.1751. Found (M+1): 604.1754.

Preparation ofrac-N-butyl-2,5-bis(3,5-dimethylphenyl)-N-(diphenylphosphanyl)phospholan-1-amine,L618 Step 1. Preparation of (3,5-dimethylphenyl)magnesium bromide

A two-necked flask, equipped with a stir bar and a Stevens (spiraltube-type) condenser, was charged with magnesium turnings (8.94 g, 368.0mmol) and THF (20 mL). 1,2-Dibromoethane (2 drops) was added to theresulting mixture. The mixture was allowed to stir for 5 min to allowactivate the magnesium turnings. In a separate container,l-bromo-3,5-dimethylbenzene (50.0 mL, 368.0 mmol) was diluted with THF(100 mL) and sucked up in a syringe. A small amount (approximately 0.5mL) of the 1-bromo-3,5-dimethylbenzene solution was added to themagnesium turnings and stirred until a color change was observed. With afan circulating air over the Stevens condenser, the remaining1-bromo-3,5-dimethylbenzene solution was slowly added over a few minutesand the reaction mixture was allowed to stir for a few minutes until therefluxing stopped. Additional THF (17.5 mL) was added to the solution.The reaction mixture was heated to 65° C. and allowed to stir overnight.A large amount of precipitate had formed. The remainder of the THF(229.5 mL) was added, and the reaction mixture was filtered through aplastic frit into an oven-dried jar. The resulting Grignard solution wastitrated using salicylaldehyde phenylhydrazone following the procedureof Love et al. (Love, B. E.; Jones, E. G. J. Org. Chem. 1999, 64, 3755)which confirmed the concentration to be 1.0 M. The Grignard solution wasused as-is in subsequent reactions.

Step 2. Preparation of (E,E)-1,4-bis(3,5-dimethylphenyl)-1,3-butadiene

(E,E)-1,4-Bis(3,5-dimethylphenyl)-1,3-butadiene was prepared accordingto a procedure adapted from Hintermann et al. (Hintermann, L.; Schmitz,M.; Chen, Y. Adv. Synth Catal. 2010, 352, 2411). Toluene (200 mL) wasadded to a small vial containing NiCl₂(tricyclohexylphosphine)₂ (3.80 g,5.51 mmol, 3 mol %). The mixture was stirred and thiophene (14.7 mL,183.6 mmol) and (3,5-dimethylphenyl)magnesium bromide (367.2 mL, 1.0 M,367.2 mmol) were added sequentially. The reaction vial was heated to 86°C. while stirring was continued. The reaction was monitored by GC/MS.Upon completion the reaction mixture was cooled, diluted with 2-4volumes of toluene, and quenched by careful addition of an equal volumeof saturated aqueous NH₄Cl (caution: H₂S gas is generated). The organicphase was washed with equal volumes of HCl (2.4 M), NaOH (2 M), andwater and was then dried over anhydrous MgSO₄. The solution was filteredand concentrated on a rotary evaporator. Purification of the materialwas achieved by chromatography on silica gel using a mixture of ethylacetate/hexanes as an eluent. Volatiles were removed under vacuum,yielding a pale yellow powder (11.00 g, 23%). ¹H NMR (400 MHz, CDCl₃) δ7.07 (s, 4H), 6.93 (d, J=12.2 Hz, 2H), 6.89 (s, 2H), 6.60 (d, J=14.0 Hz,2H), 2.33 (s, 12H). ¹H NMR (400 MHz, C₆D₆) δ 7.07 (s, 2H), 7.01-6.90 (m,1H), 6.76 (s, III), 6.66-6.55 (m, 1H), 2.18 (s, 6H), ¹³C NMR (101 MHz,C₆D₆) δ 138.07, 137.95, 133.33, 129.72, 129.62, 124.95, 21.38.

Step 3. Preparation of(1S,2R,5S)-1-(dimethylamino)-2,5-bis(3,5-dimethylphenyl)-2,5-dihydrophosphole1-oxide

In a reaction not carried out in a glovebox, dimethylphosphoramidousdichloride (4.30 g, 37.4 mmol) was added to a stirred suspension ofaluminum chloride (4.72 g, 35.4 mmol) in dichloromethane (50 mL) in alarge jacketed multi-neck flask purged with nitrogen. After 45 min, thecolorless solution that had formed and a solution of(E,E)-1,4-bis(3,5-dimethylphenyl)-1,3-butadiene (8.00 g, 34.1 mmol) indichloromethane (125 mL) were each cooled to 0° C. After cooling, the1,4-(3,5-dimethylphenyl)butadiene solution was slowly added to themixture of dimethylphosphoramidous dichloride and aluminum chloride. Themixture was allowed to stir overnight at 0° C. A suspension of aqueousEDTA (ethylenediamine tetraacetic acid, 0.2 M, 200 mL) and saturatedNaHCO₃ (100 mL) cooled in ice water was then added to the reactionmixture. The mixture was stirred at 0° C. for 4 h, filtered throughCelite, decanted, and the aqueous layer was extracted withdichloromethane. The organic layers were washed with NaHCO₃, 1.0 M HCl,brine, and dried over anhydrous MgSO₄. The volatiles were removed undervacuum to yield a yellow solid. The yellow solid was triturated withdiethyl ether, the solid was collected by filtration, washed withadditional diethyl ether, and dried. (Yield: 6.63 g, 50%). ¹H NMR (400MHz, CDCl₃) δ 6.94 (s, 4H), 6.86 (s, 2H), 6.49 (d, J=29.0 Hz, 1H), 4.22(d, J=18.7 Hz, 1H), 2.29 (s, 12H), 1.93 (d, J=8.3 Hz, 6H), ¹³C NMR (101MHz, CDCl₃) δ 138.02 (d, J=2.5 Hz), 135.79 (d, J=8.2 Hz), 130.84 (d,J=16.9 Hz), 128.39 (d, J=2.9 Hz), 125.06 (d, J=4.8 Hz), 77.36, 49.13 (d,J=71.7 Hz), 36.22 (d, J=1.8 Hz), 21.39. ³¹P NMR (162 MHz, CDCl₃) δ69.13.

Step 4. Preparation ofrac-1-(dimethylamino)-2,5-bis(3,5-dimethylphenyl)phospholane-1-oxide

In a reaction not carried out in a glovebox, an 800-mL stainless steelpressure reactor was charged with(1S,2R,5S)-1-(dimethylamino)-2,5-bis(3,5-dimethylphenyl)-2,5-dihydrophosphole1-oxide (6.10 g, 17.25 mmol), 10% Pd/C (918 mg, 0.086 mmol, 5 mol %),and methanol (200 mL). The reactor was purged with nitrogen andhydrogen, and then pressurized to 500 psi (3.45 MPa) of hydrogen andstirred for 8 hr at room temperature. Under an atmosphere of nitrogen,the solution was filtered through a plug of Celite (danger: methanol andPd/C can spark a lire in the presence of oxygen; perform under inertatmosphere), and the volatiles were removed under vacuum. The solid wasredissolved in CH₂Cl₂, filtered through Celite, and the volatiles wereremoved under vacuum. (Yield: 5.8 g, 94%; purity: 99.4%). On a plasticfilter funnel, the solid was washed with acetone to remove traceimpurities. The solid was dried under vacuum and then analyzed by NMRspectroscopy, confirming the removal of the impurities (Yield: 4.2 g,68%). ¹H NMR (400 MHz, C₆D₆) δ 7.13 (s, 2H), 6.97 (s, 2H), 6.76 (s, 1H),6.72 (s, 1H), 3.53 (ddd, J=24.4, 13.0, 7.5 Hz, 1H), 2.99-2.84 (m, 1H),2.20 (s, 6H), 2.15 (s, 6H), 2.15 (s, 3H), 2.12 (s, 3H), 2.09-1.99 (m,2H), 1.95 (ddt, J=14.0, 7.5, 3.1 Hz, 1H), 1.76-1.53 (m, 1H), ¹³C NMR(101 MHz, C₆D₆) δ 137.90 (d, J=4.6 Hz), 137.73 (d, J=2.2 Hz), 137.70 (d,J=1.7 Hz), 137.55 (d, J=5.0 Hz), 128.60 (d, J=2.1 Hz), 128.18 (d, J=2.5Hz), 127.53, 127.48, 125.37 (d, J=5.0 Hz), 47.72 (d, J=74.1 Hz), 42.75(d, J=11.6 Hz), 35.92 (d, J=2.2 Hz), 30.57 (d, J=11.9 Hz), 27.50 (d,J=9.1 Hz), 21.51, 21.40. ³¹P NMR (162 MHz, C₆D₆) δ 56.62.

Step 5. Preparation ofrac-1-chloro-2,5-bis(3,5-dimethylphenyl)phospholane

Rac-1-(Dimethylamino)-2,5-bis(3,5-dimethylphenyl)phospholane-1-oxide(2.36 g, 6.64 mmol) was mixed in ether (total reaction volume of 30 mL).Pyridine (0.59 mL, 7.30 mmol) and trichlorosilane (0.38 mL, 7.30 mmol)were sequentially added and the mixture was stirred overnight (˜18 h) atambient temperature. The volatiles were removed and pentane (10 mL) wasadded to the resulting slurry, which was stirred for a few minutes andthen filtered through a plug of activated acidic alumina. The filtratewas concentrated, placed in a freezer at −35° C. overnight to form awhite precipitate. The solvent was decanted and the solid wasredissolved in pentane and again placed in the freezer to precipitate awhite solid after a few minutes. The solid was isolated by filtration,and dried under vacuum (Yield: 1.95 g, 83%). ¹H NMR (400 MHz, C₆D₆) δ7.00 (s, 2H), 6.80 (s, 2H), 6.75 (s, 1H), 6.72 (s, 1H), 3.84 (td, J=8.9,2.3 Hz, 1H), 3.24 (ddd, J=33.3, 12.5, 5.7 Hz, 1H), 2.56 (qdd, J=12.2,6.8, 3.4 Hz, 1H), 2.43 (dtdd, J=13.4, 8.3, 6.7, 1.6 Hz, 1H), 2.16 (d,J=6.9 Hz, 12H), 1.80-1.63 (m, 1H), ¹³C NMR (101 MHz, C₆D₆) δ 141.82,141.62, 138.12, 137.44, 136.64, 128.30 (d, J=2.4 Hz), 126.14, 125.66,57.84 (d, J=32.1 Hz), 53.52 (d, J=31.1 Hz), 34.50, 31.69, 21.03. ³¹P NMR(162 MHz, CDCl₃) δ 137.06.

Step 6. Preparation ofrac-N-butyl-2,5-bis(3,5-dimethylphenyl)phospholan-1-amine

A 40-mL, oven-dried vial was charged withrac-1-chloro-2,5-bis(3,5-dimethylphenyl) phospholane (376 mg, 1.14 mmol)and pentane (20 mL). A separate vial was charged with n-butylamine (0.83mL, 11.4 mmol) and pentane (10 mL). The reagents were cooled to −30° C.,and the n-butylamine solution was slowly added (while stirring) to thesolution of rac-1-chloro-2,5-bis(3,5-dimethylphenyl) phospholane,allowing it to reach room temperature. After stirring for 30 min, analiquot was analyzed by NMR spectroscopy which confirmed completeconversion. The slurry which resulted was filtered through a plug ofneutral alumina. The alumina was then rinsed with an additional 10 mL ofpentane. The filtrate was dried under vacuum for 1 hr, then dissolved ina minimum amount of pentane, and placed in the freezer at −35° C.Overnight a white precipitate was formed, which was then isolated usinga plastic filter funnel. Analysis by NMR spectroscopy revealed thepresence of residual n-butylamine. The solid was recrystallized frompentane. The white powder was dried under vacuum and analyzed by NMRspectroscopy which confirmed complete removal of residual n-butylamine(Yield: 306 mg, 73%). ¹H NMR (400 MHz, C₆D₆) δ 7.09 (s, 2H), 6.91 (s,2H), 6.76 (s, 1H), 6.75 (s, 1H), 3.14 (ddd, J=21.6, 12.6, 6.0 Hz, 1H),3.04-2.93 (m, 1H), 2.55 (ddq, J=12.6, 10.4, 6.9 Hz, 1H), 2.41-2.25 (m,1H), 2.23 (s, 12H), 2.22-2.08 (m, 1H), 1.91 (qdd, J=12.5, 5.1, 2.6 Hz,1H), 1.70 (qdd, J=12.6, 5.1, 2.5 Hz, 1H), 1.11 (m, 1H), 1.07-0.85 (m,4H), 0.69 (t, J=6.9 Hz, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 144.41 (d, J=17.8Hz), 140.13, 137.87, 137.65-13746 (m), 127.41 (d, J=1.8 Hz), 126.29 (d,J=3.2 Hz), 126.15, 126.07, 56.17 (d, J=14.3 Hz), 50.55 (d, J=22.3 Hz),47.95 (d, J=23.1 Hz), 35.56 (d, J=6.9 Hz), 34.68, 31.93 (d, J=2.2 Hz),21.55 (d, J=2.0 Hz), 20.11, 14.05. ³¹P NMR (162 MHz, C₆D₆) δ 72.65.

Step 7. Preparation ofrac-N-butyl-2,5-bis(3,5-dimethylphenyl)-N-(diphenylphosphanyl)-phospholan-1-amine,L618

A cold (−35° C.) solution of iododiphenylphosphine (0.212 g, 0.680 mmol)in pentane (3 mL) was added dropwise to a cold (−35° C.) solution ofrac-N-butyl-2,5-bis(3,5-dimethylphenyl)phospholan-1-amine (250 mg, 0.680mmol) and triethylamine (0.072 g, 0.71 mmol) in pentane (3 mL) causingimmediate precipitation of a white powder. An aliquot was analyzed byNMR spectroscopy, continuing complete conversion to the desired product.The pentane slurry was filtered through a small alumina plug, and thesolvent was removed under vacuum. A minimum amount of pentane was addedto the solid, and the material was placed in the freezer (−35° C.).Overnight a white solid precipitated. The solution was decanted, and theresulting solid was dried under vacuum (Yield: 260 mg, 69%). ¹H NMR (400MHz, C₆D₆) δ 7.48 (tt, J=6.5, 1.6 Hz, 2H), 7.23 (s, 2H), 7.19-7.10 (m,4H), 7.01 (s, 3H), 7.00-6.93 (m, 3H), 6.87 (ddd, J=8.4, 6.8, 1.6 Hz,2H), 6.78 (d, J=10.8 Hz, 2H), 4.08 (ddt, J=12.3, 7.3, 4.7 Hz, 1H), 3.46(ddd, J=24.2, 13.3, 5.5 Hz, 1H), 3.29-3.13 (m, 1H), 3.11-2.88 (m, 1H),2.57-2.39 (m, 1H), 2.31 (td, J=10.2, 4.9 Hz, 1H), 2.24 (s, 6H), 2.18 (s,6H), 1.71 (qdt, J=12.9, 4.7, 2.1 Hz, 1H), 1.04-0.84 (m, 1H), 0.74-0.49(m, 2H), 0.43 (t, J=7.0 Hz, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 144.61 (d,J=20.6 Hz), 141.12 (d, J=22.9 Hz), 139.37 (d, J=2.5 Hz), 139.23, 139.07,137.79 (d, J=2.9 Hz), 133.30 (d, J=19.8 Hz), 132.77 (d, J=20.2 Hz),128.68, 128.49 (d, J=5.3 Hz), 128.37, 127.89, 127.55-127.44 (m), 127.29(d, J=1.7 Hz), 127.26 (d, J=1.7 Hz), 126.86, 126.78, 56.45-55.86 (m),54.81 (dd, J=34.0, 6.8 Hz), 52.74-51.81 (m), 36.79, 34.46 (d, J=6.6 Hz),33.24 (d, J=3.4 Hz), 33.16 (d, J=3.3 Hz), 21.48, 20.04, 13.97. ³¹P NMR(162 MHz, C₆D₆) δ 100.18-98.20 (broad d, 1P), 56.83 (d, J=26.5 Hz, 1P).

Preparation ofrac-N-cyclohexyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L619 Step 1. Preparation ofrac-N-cyclohexyl-2,5-diphenylphospholan-1-amine

A solution of cyclohexylamine (0.38 mL, 3.3 mmol) in hexanes (5.00 mL)was added to a solution of rac-1-chloro-2,5-diphenyl-phospholane (0.30g, 1.1 mmol) in hexanes (5.00 mL). The reaction mixture was stirred atroom temperature overnight. The solid was removed by filtration and theresulting solution was passed through a 5-cm plug of activated neutralalumina. The solvent was evaporated under vacuum to give a white solid.Yield 0.35 g (94.6%). ¹H NMR (400 MHz, C₆D₅CD₃) δ 7.30 (dt, J=8.0, 1.6Hz, 2H), 7.19 (dt, J=17.0, 7.6 Hz, 4H), 7.11-7.02 (m, 4H), 3.03 (ddd,J=22.3, 12.4, 6.0 Hz, 1H), 2.83 (ddd, J=12.6, 7.1, 5.9 Hz, 1H),2.28-2.12 (m, 1H), 2.04 (m, 1H), 1.80 (m, 1H), 1.72-1.51 (m, 3H),1.51-1.21 (m, 3H), 1.03 (dd, J=10.8, 7.3 Hz, 2H), 0.98-0.73 (m, 4H),0.58-0.36 (m, 1H), ¹³C NMR (101 MHz, C₆D₅CD₃) δ 144.00 (d, J=17.8 Hz),140.05, 128.24, 127.99 (d, J=3.3 Hz), 127.94, 127.43, 125.47 (d, J=2.4Hz), 125.13 (d, J=1.8 Hz), 56.81 (d, J=15.3 Hz), 56.15 (d, J=24.6 Hz),49.78 (d, J=22.1 Hz), 36.80 (d, J=5.9 Hz), 36.08 (d, J=5.2 Hz), 33.59(d, J=3.2 Hz), 31.39 (d, J=2.1 Hz), 25.67, 25.11 (d, J=13.9 Hz). ³¹P NMR(162 MHz, C₆D₅CD₃) δ 71.46.

Step 2. Preparation ofrac-N-cyclohexyl-N-(diphenylphosphanyl)-2,5-diphenylphospholan-1-amine,L619

A cold solution (−30° C.) of triethylamine (0.058 g, 0.57 mmol)dissolved in CH₂Cl₂ (0.576 mL), was added to a cold (−30° C.) solutionof rac-N-cyclohexyl-2,5-diphenylphospholan-1-amine (0.16 g, 0.47 mmol)dissolved in CH₂Cl₂ (1.60 mL). Hie resulting mixture was stirred for 10min and placed in a freezer at −30° C. for 30 minutes. A cold (−30° C.)solution of bromodiphenylphosphine (0.13 g, 0.47 mmol) in 1.26 mL ofCH₂Cl₂ was added to the cold mixture. The solution was stirred atambient temperature overnight. Solvent was removed under vacuum. Thecrude product was redissolved in a diethyl ether and toluene (50/50 v/v)solvent mixture (5 mL) and filtered through a 5-cm plug of activatedneutral alumina. The solvent was evaporated under vacuum giving solidproduct which was recrystallized from cold pentane at −30° C. to yieldpure product. Yield 0.16 g (63.9%). ¹H NMR (400 MHz, C₆D₆, 70° C.) δ7.49 (d, J=7.0 Hz, 2H), 7.22 (d, J=7.6 Hz, 3H), 7.16-7.07 (m, 2H),7.07-6.93 (m, 11H), 6.86 (h, J=6.3 Hz, 2H), 4.09 (s, 1H), 3.34 (ddd,J=25.7, 13.1, 5.7 Hz, 1H), 2.98 (s, 1H), 2.86 (qdd, J=11.3, 7.6, 3.4 Hz,1H), 2.42 (td, J=15.4, 14.0, 6.4 Hz, 1H), 2.14 (tt, J=11.1, 5.5 Hz, 1H),1.78 (q, J=12.0 Hz, 1H), 1.69-1.51 (m, 1H), 1.48-1.30 (m, 2H), 1.30-1.14(m, 3H), 1.11-0.92 (m, 1H), 0.79 (tq, J=23.4, 12.4 Hz, 3H). ¹³C NMR (101MHz, C₆D₆) δ 144.08 (d, J=20.7 Hz), 141.19 (d, J=24.0 Hz), 139.72,139.23 (d, J=2.8 Hz), 133.10 (d, J=23.6 Hz), 132.51, 128.69 (d, J=3.1Hz), 128.53, 128.23-127.96 (m), 127.85, 127.37, 127.32, 125.51 (d, J=2.5Hz), 125.15 (d, J=1.8 Hz), 61.24 (d, J=14.7 Hz), 50.42 (d, J=23.3 Hz),36.18 (d, J=3.9 Hz), 35.69 (d, J=10.2 Hz), 34.77, 33.02-32.64 (m),26.19, 25.96, 25.24. ³¹P NMR (162 MHz, C₆D₆, 70° C.) δ 83.47, 58.30.HRMS: Expected (M+1): 522.2473; Found (M+1): 522.2483.

Preparation of(rac)-N-(bis(3,5-di-tert-butyl-4-methoxyphenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L620 Step 1. Preparation ofbis(3,5-di-t-butyl-4-methoxyphenyl)iodophosphine

Bis(3,5-di-t-butyl-4-methoxyphenyl)chlorophosphine (0.90 g, 1.8 mmol)was dissolved in toluene (4.0 mL). Iodotrimethylsilane (0.30 mL, 2.1mmol) was added and the orange solution was stirred at ambienttemperature overnight. Some yellow solid had formed. The mixture wasfiltered to remove the yellow solid and the filtrate was concentratedunder vacuum to yield the product. Yield (1.0 g, 97%). ¹H NMR (400 MHz,C₆D₆) δ 7.90 (d, J=7.7 Hz, 4H), 3.31 (s, 6H), 1.37 (s, 36H). ¹³C NMR(101 MHz, C₆D₆) δ 161.96, 144.37 (d, J=6.1 Hz), 133.06, 132.81, 64.21,36.20, 32.12. ³¹P NMR (162 MHz, C₆D₆) δ 47.18.

Step 2. Preparation of(rac)-N-(bis(3,5-di-tert-butyl-4-methoxyphenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L620

A cold (−30° C.) solution ofbis(3,5-di-t-butyl-4-methoxyphenyl)iodophosphine (0.29 g, 0.48 mmol) intoluene (5.0 mL) was added dropwise to a cold (−30° C.) solution of(rac)-N-butyl-2,5-diphenylphospholan-1-amine (0.15 g, 0.48 mmol) andtriethylamine (0.074 uL, 0.53 mmol) in toluene (5.0 mL), causingimmediate solid formation. After mixing, the volatiles were removedunder vacuum. The residue was extracted with ether and filtered througha plug of activated neutral alumina. The volatiles were removed to yieldthe product as a white solid. Yield (0.31 g, 81%). ¹H NMR (400 MHz,C₆D₆) δ 7.77 (t, J=3.1. Hz, 2H), 7.56-7.44 (m, 2H), 7.40 (d, J=6.7 Hz,2H), 7.33-7.23 (m, 2H), 7.21-7.11 (m, 4H), 7.08-7.00 (m, 1H), 7.00-6.91(m, 1H), 4.59-4.16 (m, 1H), 3.38 (d, J=10.9 Hz, 6H), 3.31 (s, 5H),3.24-3.04 (m, 3H), 1.49 (d, J=3.0 Hz, 3H), 1.33 (s, 36H), 0.40 (d, J=7.3Hz, 3H). ¹³C NMR (101 MHz, C₆D₆) δ 160.36-160.07 (m), 144.84 (d, J=21.4Hz), 143.48-143.22 (m), 142.73 (d, J=6.6 Hz), 139.20 (d, J=1.7 Hz),135.18 (d, J=19.5 Hz), 133.33 (t, J=13.5 Hz), 131.88 (d, J=23.1 Hz),130.84 (t, J=4.4 Hz), 130.31 (d, J=21.2 Hz), 128.80 (t, J=2.8 Hz),128.39 (d, J=9.8 Hz), 128.31, 127.93 (d, J=1.4 Hz), 125.50 (dd, J=15.7,2.2 Hz), 63.88 (d, J=5.6 Hz), 63.58, 36.82, 35.68, 35.56 (d, J=4.6 Hz),34.24 (d, J=7.3 Hz), 31.93, 31.86 (d, J=4.6 Hz), 19.77, 13.52. ³¹P NMR(162 MHz, C₆D₆) δ 100.55 (d, J=25.7 Hz), 57.14 (d, J=25.7 Hz). HRMS(ESI-TOF) m/z: [M+H]+ Calcd for C₅₀H₇₁NO₂P₂ 780.5033; Found 780.5048.

Preparation of(2S,5S)—N-(bis(2,6-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L627 Step 1. Preparation ofbis(2,6-difluorophenyl)dimethylaminophosphine

1-Bromo-3,5-difluorobenzene (19.00 g, 98.45 mmol) was added slowlydropwise to a chilled (−90 to −85° C. (liquid nitrogen/acetone))solution of n-butyllithium (42.0 mL, 2.34 M in hexanes, 98.3 mmol) inether (250 mL) such that the temperature did not exceed −85° C. Thetemperature was allowed to increase to between −78 and −74° C. for 2hours (dry ice bath) with no formation of white precipitate, even afterwarming to −65° C. for 1 h. The mixture was cooled to −78° C. and asolution of dimethylphosphoramidous dichloride (7.161 g, 49.06 mmol) inether (20 mL total) was added slowly dropwise at a rate such that thetemperature did not exceed −65° C. Precipitate formed during theaddition and the colorless mixture turned light brown. The reactionmixture was allowed to warm to ambient temperature while stirringovernight. The color has turned red. The reaction mixture was filteredand the volatiles were removed under reduced pressure to give a deep redsolid. The solid was extracted with hexane, filtered, and the volatileswere removed under reduced pressure to give large colorless crystalscoated with red liquid. The liquid was decanted. The crystals werecollected on a frit, washed with hexane, and dried under reducedpressure to give bulk crystalline material which is pink due to somesurface red liquid. Yield=7.135 g (48.3%). ¹H NMR (400 MHz, CDCl₃) δ7.32-7.21 (m, 1H), 6.89-6.73 (m, 2H), 2.73 (dp, J=10.5, 0.7 Hz, 3H), ¹³CNMR (101 MHz, CDCl₃) δ 163.16 (dt, J=246.7, 10.2 Hz), 130.82 (t, J=10.9Hz), 115.15 (dtt, J=34.4, 23.7, 3.1 Hz), 111.69-111.06 (m), 42.46 (dt,J=17.3, 2.1 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 25.62 (p, J=31.8 Hz). ¹⁹FNMR (376 MHz, CDCl₃) δ −104.67 (dt, J=31.7, 7.0 Hz).

Step 2. Preparation of bis(2,6-difluorophenyl)chlorophosphine

Anhydrous HCl in ether (35.0 mL, 2 M, 70.0 mmol) is added to a solutionof bis(2,6-difluorophenyl)dimethylaminophosphine (7.00 g, 23.24 mmol) inmethylene chloride (20 mL) causing decolorizing of the red-orangereaction mixture and formation of precipitate. The reaction mixture isstirred for 30 minutes. The mixture is filtered and the volatilesremoved under reduced pressure. The residue is extracted with ether andfiltered. The volatiles are removed under reduced pressure to give theproduct as a light yellow solid, 6.492 g, 95.5%. ¹H NMR (500 MHz, CDCl₃)δ 7.42-7.41 (m, 1H), 6.91 (td, J=8.2, 2.5 Hz, 2H), ¹³C NMR (126 MHz,CDCl₃) δ 163.69 (dm, J=252.0 Hz), 133.73-133.33 (m), 113.50-112.37 (m),112.15-111.48 (m). ³¹P NMR (162 MHz, CDCl₃) δ 39.58 (p, J=43.5 Hz). ¹⁹FNMR (376 MHz, CDCl₃) δ −100.55 (dt, J=43.5, 7.0 Hz).

Step 3. Preparation of bis(2,6-difluorophenyl)iodophosphine

Iodotrimethylsilane (5.308 g, 26.53 mmol) was slowly added to a solutionof bis(2,6-difluorophenyl)chlorophosphine (6.40 g, 21.9 mmol) inmethylene chloride (20 mL). The reaction mixture instantly turned deepyellow. The mixture was allowed to stir for 1 hour. The volatiles wereremoved under reduced pressure. The residue was extracted with ether,filtered, and the volatiles were removed under reduced pressure to givethe product as an orange-yellow crystalline solid, 8.3852 g, 99.8%. ¹HNMR (500 MHz, CDCl₃) δ 7.46-7.33 (m, 1H), 6.91 (dtd, J=10.6, 8.1, 7.4,3.3 Hz, 2H), ¹³C NMR (126 MHz, CDCl₃) δ 163.85 (dm, J=251.8 Hz),133.43-132.88 (m), 111.99-111.35 (m), 110.35-108.83 (m). ³¹P NMR (202MHz, C₆D₆) δ −29.81 (p, J=36.9 Hz). ¹⁹F NMR (470 MHz, CDCl₃) δ −96.87(dt, J=36.4, 6.8 Hz).

Step 4. Preparation of(2S,5S)—N-(bis(2,6-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L627

About 90% of a solution of bis(2,6-difluorophenyl)iodophosphine (0.394g, 1.03 mmol) in diethyl ether (6 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.3198 g, 1.03 mmol) andtriethylamine (1.34 g, 13.2 mmol) in diethyl ether (6 mL) with formationof precipitate. ³¹P NMR spectra showed a slight excess of phospholane tobe present. Additional bis(2,6-difluorophenyl)iodophosphine solution wasadded. The reaction mixture was stirred overnight. ³¹P NMR spectra stillshowed about 3% phospholane to be present. The rest of thebis(2,6-difluorophenyl)iodophosphine solution was added. The reactionmixture was stirred for several hours, then filtered, and the volatileswere removed under reduced pressure. The residue was extracted withether, filtered, and the volatiles were removed under reduced pressureto give a beige solid. The residue was triturated with hexanes,filtered, and dried under reduced pressure to give the product as abeige powder, 0.4365 g, 74.89%. ¹H NMR (500 MHz, CDCl₃) δ 7.38-7.26 (m,7H), 7.21-7.17 (m, 1H), 7.15 (ddt, J=8.2, 6.4, 1.5 Hz, 1H), 7.00 (t,J=7.7 Hz, 2H), 6.89 (t, J=7.4 Hz, 1H), 6.85 (td, J=8.2, 2.2 Hz, 1H),6.63 (td, J=8.2, 2.5 Hz, 2H), 4.11 (ddt, J=12.2, 7.9, 4.5 Hz, 1H), 3.50(dddd, J=24.9, 13.4, 5.3, 1.7 Hz, 1H), 3.24-3.01 (m, 2H), 2.71 (ddddd,J=14.4, 13.0, 7.8, 5.1, 1.1 Hz, 1H), 2.40 (dq, J=17.0, 5.3 Hz, 1H), 1.82(tdd, J=12.9, 11.2, 5.2 Hz, 1H), 0.71 (dddd, J=21.0, 15.0, 9.3, 3.7 Hz,3H), 0.42 (t, J=7.2 Hz, 3H), 0.41-0.28 (m, 1H), ¹³C NMR (101 MHz, CDCl₃)δ 163.51 (ddd, J=247.8, 11.4, 8.8 Hz), 162.57 (dt, J=247.4, J=10.2 Hz),143.97 (d, J=20.7 Hz), 138.02 (d, J=2.3 Hz), 131.82 (t, J=11.0 Hz),129.88 (t, J=10.8 Hz), 128.30 (dm, J=3.0 Hz), 128.01 (d, J=8.4 Hz),127.66 (d, J=1.3 Hz), 125.63 (d, J=2.6 Hz), 125.43 (d, J=1.9 Hz),116.27-114.92 (m), 111.91-111.49 (m), 111.49-111.07 (m), 58.69 (dm,J=33.5 Hz), 55.44 (dd, J=21.9, 17.7 Hz), 52.16 (dd, J=21.4, 7.0 Hz),36.42, 33.87 (d, J=6.9 Hz), 32.57 (dd, J=9.0, 3.7 Hz), 19.60, 13.42. ³¹PNMR (202 MHz, CDCl₃) δ 109.47 (d, J=29.8 Hz), 15.41 (pd, J=39.5, 30.0Hz). ¹⁹F NMR (470 MHz, CDCl₃) δ −101.75 (dt, J=39.7, 7.6 Hz), −103.51(dt, J=39.2, 7.4 Hz). HRMS: Expected (M+1): 568.1868. Found (M+1):568.1940.

Preparation of(2S,5S)—N-(bis(3,5-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L628 Step 1. Preparation ofbis(3,5-diflourophenyl)dimethylaminophosphine

1-Bromo-3,5-difluorobenzene (19.469 g, 100.9 mmol) was added slowlydropwise to a chilled (−100 to −93° C. (liquid nitrogen/acetone))solution of n-butyllithium in hexanes (42.0 mL, 2.39 M, 100 mmol total)in ether (250 mL) such that the temperature did not exceed −88° C. Thetemperature was allowed to increase to between −78 and −74° C. for 1hours (dry ice bath) with formation of white precipitate. A solution ofdimethylphosphoramidous dichloride (7.030 g, 48.17 mmol) in ether (20 mLtotal) was added slowly dropwise at a rate such that the temperature didnot exceed −64° C. The reaction mixture was allowed to warm whilestirring overnight. By morning the temperature had reached 14° C. andthe mixture color was reddish-purple. The flask was taken into theglovebox. The volatiles were removed under high vacuum to give areddish-brown solid. The solid was extracted with hexane, filtered, andthe volatiles were removed under reduced pressure to give a red oil. Theoil was re-extracted with hexane, filtered from a trace of gray solid,and the volatiles were removed under reduced pressure to give theproduct as a red oil, 6.532 g, 44.3%. ¹H NMR (400 MHz, CDCl₃) δ 6.89(tdd, J=6.4, 2.3, 1.5 Hz, 4H), 6.77 (ttd, J=8.8, 2.3, 0.9 Hz, 2H), 2.65(d, J=9.6 Hz, 6H). ¹³C NMR (101 MHz, CDCl₃) δ 163.00 (ddd, J=252.1,11.3, 8.0 Hz), 142.66 (dt, J=20.9, 5.5 Hz), 114.05 (ddd, J=20.5, 18.2,6.4 Hz), 104.28 (td, J=25.4, 1.6 Hz), 41.78 (d, J=16.0 Hz). ³¹P NMR (162MHz, CDCl₃) δ 65.58. ¹⁹F NMR (376 MHz, CDCl₃) δ −109.14 (m).

Step 2. Preparation of bis(3,5-difluorophenyl)chlorophosphine

Anhydrous HCl in ether (35.0 mL, 2 M, 70.0 mmol) was added to a cooled(ice bath) solution of bis(3,5-difluorophenyl)dimethylaminophosphine(8.00 g, 26.6 mmol) in methylene chloride (20 mL), causing decolorizingof the yellow-orange reaction mixture and formation of precipitate. Thereaction mixture was stirred for several days. The volatiles wereremoved under reduced pressure. The residue was extracted with ether andfiltered. The volatiles were removed under reduced pressure to give theproduct as pale yellow liquid. The yield was 7.5385 g, 94.8%. NMR (400MHz, CDCl₃) δ 7.10 (dddd, J=7.8, 5.6, 2.3, 1.5 Hz, 4H), 6.87 (tt, J=8.7,2.3 Hz, 2H), ¹³C NMR (101 MHz, CDCl₃) δ 163.00 (ddd, J=254.0, 11.4, 9.6Hz), 141.96 (dt, J=37.0, 6.5 Hz), 114.51-113.89 (m), 106.42 (td, J=25.2,1.4 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 75.35. ¹⁹F NMR (376 MHz, CDCl₃) δ−107.44-−107.51 (m).

Step 3. Preparation of bis(3,5-difluorophenyl)iodophosphine

Iodotrimethylsilane (6.081 g, 30.39 mmol) was added to a solution ofbis(3,5-difluorophenyl)chlorophosphine (7.410 g, 25.32 mmol) in ether(10 mL). The reaction mixture instantly turned deep yellow. The mixturewas allowed to stir overnight. The reaction mixture was filtered and thevolatiles were removed under reduced pressure to give 7.3738 g of crudeproduct. The residue was extracted with ether, filtered, and thevolatiles were removed under reduced pressure to give the product as adark yellow oil.). Some solid particles were present. NMR spectra showedabout 88% purity. The product was dissolved in ether, filtered from somebrownish solid, and the volatiles were removed under reduced pressure togive a yellow oil. The product was subjected to trap-to-trapdistillation: The water bath temperature was 85° C. at the pot end andliquid nitrogen at the receiver end. The vacuum was achieved on an oildiffusion pump vacuum line (0.6 mTorr). Only a very small amount(0.1-0.2 g) of dark yellow oil distilled over. The pot material appearsto be less yellow. By ³¹P NMR, the distillate has peaks at 48.1 ppm(69%, undesired product), 33.8 ppm (9%, desired product), 0.6 ppm (22%,new undesired product), while the pot is enriched in desired product:48.1 ppm (4.3%, undesired product), 33.8 ppm (91.6%, desired product),−9.3 ppm (4.1%, old undesired product). The pot residue of this firstdistillation was distilled in a second distillation at a slightly highertemperature of 90° C. to give the product as quite pure yellow oil,3.5184 g, 35.18%. ¹H NMR (400 MHz, CDCl₃) δ 7.18-7.13 (m, 2H), 6.83 (tt,J=8.6, 2.3 Hz, 1H), 13C NMR (101 MHz, CDCl₃) δ 162.73 (ddd, J=254.0,11.5, 8.8 Hz), 138.28 (dt, J=42.1, 6.7 Hz), 116.77-116.10 (m), 106.28(td, J=25.2, 1.5 Hz). ³¹P NMR (162 MHz, CDCl₃) δ 30.22. ¹⁹F NMR (376MHz, CDCl₃) δ −107.32-−107.42 (m).

Step 4. Preparation of(2S,5S)—N-(bis(3,5-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L628

A solution of bis(3,5-difluorophenyl)iodophosphine (0.518 g, 1.35 mmol)in diethyl ether (6 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.400 g, 1.28 mmol) andtriethylamine (1.300 g, 12.84 mmol) in diethyl ether (6 mL) withformation of precipitate. The reaction mixture was stirred overnight.³¹P NMR spectra showed the reaction to be complete. The reaction mixturewas filtered, and the volatiles were removed under reduced pressure. Theresidue was extracted with ether, filtered, and the volatiles wereremoved under reduced pressure to give a yellow oil. The residue wastriturated with hexanes, but the product all dissolved except for atrace of white solids. The solution was filtered, and the volatiles wereremoved under reduced pressure to give a yellow oil that solidified to ayellow solid. Yield: 0.6745 g, 92.5%. ¹H NMR (500 MHz, CDCl₃) δ 7.39 (d,J=7.6 Hz, 2H), 7.36-7.30 (m, 2H), 7.29-7.21 (m, 5H), 7.20 (d, J=7.4 Hz,1H), 6.87-6.76 (m, 3H), 6.66 (tm, J=8.8 Hz, 1H), 6.18 (td, J=6.2, 2.0Hz, 2H), 3.77 (tt, J=7.9, 3.9 Hz, 1H), 3.60 (ddd, J=25.0, 13.2, 5.8 Hz,1H), 2.93 (dddt, J=13.3, 11.3, 9.0, 3.6 Hz, 2H), 2.83 (dddd, J=15.6,9.4, 5.3.1.7 Hz, 1H), 2.60 (tdd, J=12.7, 9.9, 4.8 Hz, 1H), 2.44 (dq,J=11.0, 5.5 Hz, 1H), 1.82 (dddd, J=15.5, 13.2, 7.8, 5.4 Hz, 1H),0.93-0.69 (m, 3H), 0.64-0.55 (m, 1H), 0.52 (td, J=7.2, 1.6 Hz, 3H). ¹³CNMR (126 MHz, CDCl₃) δ 163.62 (ddd, J=63.0, 11.3, 8.2 Hz), 161.61 (ddd,J=61.7, 11.4, 8.3 Hz), 143.90 (dt, J=27.8, 5.4 Hz), 143.00 (d, J=20.5Hz), 141.92 (dt, J=21.1, 6.0 Hz), 138.10 (d, J=2.6 Hz), 128.56-128.47(m), 128.48 (d, J=26.5 Hz), 127.95 (d, J=8.8 Hz), 126.15 (d, J=2.0 Hz),126.07 (d, J=2.5 Hz), 114.58 (dddd, J=21.0, 19.6, 15.5, 5.6 Hz), 104.60(td, J=25.3, 1.8 Hz), 104.03 (td, J=25.3, 1.8 Hz), 56.02 (dd, J=21.9,16.3 Hz), 54.37 (dd, J=28.6, 3.8 Hz), 51.01 (dd, J=21.9, 4.4 Hz), 36.26(d, J=3.3 Hz), 33.55 (d, J=6.7 Hz), 32.71 (dd, J=6.7, 3.6 Hz), 19.57,13.42. ³¹P NMR (202 MHz, CDCl₃) d 100.26 (d, J=16.7 Hz), 58.12 (d,J=16.7 Hz). ¹⁹F NMR (470 MHz, CDCl₃) d −108.73-−108.86 (m),−109.51-−109.69 (m).

Preparation ofrac-N-cyclobutyl-N-(bis(2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L629 Step 1. Preparation ofrac-N-cyclobutyl-N-(bis(2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L629

A cold solution (−30° C.) of triethylamine (0.063 g, 0.62 mmol)dissolved in toluene (1.3 mL) was added to a cold (−30° C.) solution ofrac-AT-cyclobutyl-2,5-diphenylphospholan-1-amine (0.16 g, 0.52 mmol)dissolved in toluene (1.6 mL) and the resulting mixture was stirred for10 min. The mixture was placed in a freezer at −30° C. for 30 minutes. Acold (−30° C.) solution of bis(2-fluorophenyl)iodophosphine (0.18 g,0.52 mmol) hi 1.8 mL of toluene was added to the cooled mixture oftriethylamine and rac-N-cyclobutyl-2,5-diphenylphospholan-1-amine, withformation of a white precipitate. The reaction mixture was stirred for30 min at ambient temperature, then was filtered through a 5-cm plug ofactivated neutral alumina. The volatiles were removed under vacuumgiving solid product which was recrystallized from cold pentane at −30°C. to produce pure product. Yield 0.25 g (92%). ¹H NMR (400 MHz, C₆D₆,70° C.) δ 7.34 (d, J=7.5 Hz, 2H), 7.15 (q, J=7.3 Hz, 4H), 7.05-6.74 (m,7H), 6.68-6.46 (m, 5H), 4.47-4.30 (m, 1H), 3.65 (dt, J=16.2, 8.0 Hz,1H), 3.23 (m, 2.89 (d, J=13.6 Hz, 1H), 2.71-2.42 (m, 2H), 2.15-1.99 (m,1H), 1.90 (s, 1H), 1.74-1.51 (m, 2H), 1.28 (d, J=9.9 Hz, 2H), 1.01 (m,1H), ¹³C NMR (101 MHz, C₆D₆, 70° C.) δ 165.39 (d, J=17.9 Hz), 163.96 (d,J=17.2 Hz), 162.95 (d, J=18.1 Hz), 161.53 (d, J=16.9 Hz), 144.44 (d,J=21.7 Hz), 138.71 (d, J=2.3 Hz), 133.15 (t, J=5.5 Hz), 130.95 (d, J=8.6Hz), 129.59 (d, J=8.1 Hz), 128.34 (d, J=3.9 Hz), 128.25, 128.10, 128.01,127.86, 125.43 (dd, J=20.0, 2.3 Hz), 123.80 (dd, J=20.1, 3.2 Hz), 115.04(d, J=24.1 Hz), 114.38 (d, J=23.2 Hz), 57.83 (d, J=23.3 Hz), 53.73-51.41(m), 51.00 (dd, J=22.6, 3.7 Hz), 36.16 (d, J=1.8 Hz), 32.85 (dd, J=22.9,8.6 Hz), 31.94 (d, J=14.6 Hz), 14.37. ³¹P NMR (162 MHz, C₆D₆, 70° C.) δ81.24, 32.49. ¹⁹F NMR (376 MHz, C₆D₆) δ −103.57 (m).

Preparation ofrac-N-cyclopentyl-N-(bis(2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L630 Step 1. Preparation ofrac-N-cyclopentyl-2,5-diphenylphospholan-1-amine

A solution of cyclopentylamine (0.64 mL, 6.5 mmol) in hexanes (5.0 mL)was added to a solution of rac-1-chloro-2,5-diphenyl-phospholane (0.60g, 2.2 mmol) in hexanes (5.0 mL). The reaction mixture was stirred atroom temperature overnight. The solid was removed by filtration using adisposable filter funnel and the resulting solution was passed through a5-cm plug of activated neutral alumina. The volatiles were removed undervacuum to give a white solid. Yield 0.58 g (78%). ¹H NMR (400 MHz, C₆D₆)δ 7.29 (dt, J=8.0, 1.7 Hz, 2H), 7.17 (m, J=17.1, 7.5, 1.6 Hz, 4H),7.11-6.98 (m, 4H), 3.13-2.95 (m, 1H), 2.92-2.71 (m, 2H), 2.22-1.92 (m,2H), 1.75 (m, 1H), 1.53 (m, 1H), 1.46-1.19 (m, 2H), 1.19-0.96 (m, 4H),0.68-0.50 (m, 1H), ¹³C NMR (101 MHz, C₆D₆) δ 144.03 (d, J=18.3 Hz),139.99 (d, J=1.3 Hz), 128.34 (d, J=1.2 Hz), 128.05 (d, J=1.1 Hz), 127.94(d, J=3.4 Hz), 127.54 (d, J=8.1 Hz), 125.58 (d, J=2.4 Hz), 125.24 (d,J=1.8 Hz), 59.24 (d, J=22.4 Hz), 56.25 (d, J=15.0 Hz), 49.74 (d, J=22.3Hz), 36.01-34.91 (m), 33.58 (d, J=3.0 Hz), 31.45 (d, J=2.1 Hz), 23.03(d, J=3.4 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 68.29.

Step 2. Preparation ofrac-N-cyclopentyl-N-(bis(2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L630

A cold solution (−30° C.) of triethylamine (0.049 g, 0.48 mmol) intoluene (0.98 mL) was added to a cold (−30° C.) solution ofrac-N-cyclopentyl-2,5-diphenylphospholan-1-amine (0.13 g, 0.40 mmol) intoluene (1.3 mL) and the resulting reaction mixture was stirred for 10min. The reaction mixture was placed in a freezer at −30° C. for 30minutes. To this cooled reaction mixture was added a cold (−30° C.)solution of bis(2-fluorophenyl)iodophosphine (0.14 g, 0.40 mmol) in 1.4mL of toluene with formation of a white precipitate. The reactionmixture was stirred for 30 min at ambient temperature. The reactionmixture was filtered through a 5-cm plug of activated neutral aluminaand the volatiles were removed under vacuum giving solid product whichwas recrystallized from cold pentane at −30° C. to produce pure product.Yield 0.11 g (50.3%). ¹H NMR (400 MHz, C₆D₆, 70° C.) δ 7.37 (d, J=7.5Hz, 2H), 7.16 (t, J=7.2 Hz, 4H), 7.02 (q, J=7.8, 5.7 Hz, 2H), 6.97-6.75(m, 5H), 6.66 (dt, J=13.3, 4.5 Hz, 4H), 6.55 (d, J=6.6 Hz, 1H), 4.40 (d,J=11.5 Hz, 1H), 3.58-3.39 (m, 1H), 3.26 (m, 1H), 2.97 (s, 1H), 2.52 (m,1H), 2.05 (m, 2H), 1.50 (m, 3H), 1.35-0.75 (m, 5H), ¹³C NMR (101 MHz,C₆D₆, 70° C.) δ 144.45 (d, J=21.4 Hz), 138.75 (d, J=2.4 Hz), 133.58,133.09, 131.11 (d, J=8.8 Hz), 129.39 (d, J=8.2 Hz), 128.39 (d, J=3.0Hz), 128.23 (d, J=3.6 Hz), 128.12, 127.87, 125.45 (dd, J=15.9, 2.4 Hz),123.75 (d, J=3.4 Hz), 115.08 (d, J=24.4 Hz), 114.36 (d, J=23.1 Hz),63.81 (d, J=19.5 Hz), 51.01 (d, J=23.6 Hz), 36.68 (d, J=2.4 Hz),35.75-34.84 (m), 33.70 (d, J=14.6 Hz), 32.84, 24.02. ³¹P NMR (162 MHz,C₆D₆, 70° C.) δ 83.83, 33.05. ¹⁹F NMR (376 MHz, C₆D₆) δ −105.88 (m).

Preparation of(2S,5S)—N-(bis(2,4,6-trifluorophenyl)phosphanyl)-butyl-2,5-diphenylphospholan-1-amine,L636 Step 1. Preparation ofbis(2,4,6-trifluorophenyl)dimethylaminophosphine

1-Bromo-2,4,6-trifluorobenzene (21.022 g, 99.64 mmol) was added slowlydropwise to a chilled (−99 to −89° C. (liquid nitrogen/acetone))solution of n-butyllithium (42.0 mL, 2.35 M, 98.7 mmol) in hexanes inether (250 mL) such that the temperature did not exceed −89° C. Hietemperature was allowed to increase to between −78 and −74° C. for 2hours (dry ice bath) with no formation of precipitate. A solution ofdimethylphosphoramidous dichloride (6.860 g, 47.00 mmol) in ether (20 mLtotal) was added slowly dropwise at a rate such that the temperature didnot exceed −65° C. Precipitate formed during the addition and thecolorless reaction mixture turned light brown. The reaction mixture wasallowed to warm to ambient temperature while stirring overnight. Thecolor has turned red-brown. The reaction mixture was filtered and thevolatiles were removed under reduced pressure to give a brownish-redoil. The solid was extracted with hexane, filtered, and the volatileswere removed under reduced pressure to give a red oil. The yield was12.121 g, 76.479%. ¹H NMR (400 MHz, CDCl₃) δ 6.61 (tdd, J=8.9, 1.8, 1.1Hz, 4H), 2.70 (dt, J=10.6, 0.8 Hz, 6H) ¹³C NMR (101 MHz, CDCl₃) δ165.09-164.35 (m), 162.60-161.89 (m), 111.53-110.41 (m), 100.48 (ddd,J=30.7, 24.9, 3.3 Hz), 42.32 (dp, J=17.9, 1.9 Hz). ³¹P NMR (162 MHz,CDCl₃) δ 24.73 (td, J=31.0, 2.9 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −101.74(dt, J=31.1, 8.1 Hz), −107.33 (pd, J=8.6, 2.7 Hz).

Step 2. Preparation of bis(2,4,6-trifluorophenyl)chlorophosphine

Anhydrous HCl in ether (45.0 mL, 2 M, 90 mmol) was added to a cooled(−35° C.) solution of bis(2,4,6-trifluorophenyl)dimethylaminophosphine(12.000 g, 35.590 mmol) in methylene chloride (100 mL) with decolorizingof the orange-red reaction mixture and formation of precipitate. Thereaction mixture was stirred overnight, then filtered and the volatileswere removed under reduced pressure. The residue was extracted withether and filtered. The volatiles were removed under reduced pressure togive the product as a dark yellow liquid. By ³¹P NMR, the compoundcontains mostly desired product (pentet, δ 37.34, 91.7%),dichloro(2,4,6-trifluorophenyl)phosphine (triplet, δ 72.00, J=51.6 Hz,7.1%), and a downfield peak (singlet, δ 114.22, 1.2%). A trap-to-trapdistillation was setup to remove thedichloro(2,4,6-trifluorophenyl)phosphine. The water-white more volatilefraction was compose of desired product (80.4%),dichloro(2,4,6-trifluorophenyl)phosphine (16.3%), downfield peak (3.2%).The dark yellow pot residue was composed of desired product (97.2%),dichloro(2,4,6-trifluorophenyl)phosphine (2.9%), and no downfield peak.The distillation was continued (2^(nd) distillation): Distillate:desired product (97.5%), dichloro(2,4,6-trifluorophenyl)phosphine(2.3%), downfield peak (none). The distillate was a colorless liquidwhich solidified to a white solid, 3.924 g of white solid, 33.56%. NMR(400 MHz, CDCl₃) δ 6.74-6.65 (m, 1H). ¹³C NMR (126 MHz, CDCl₃) δ 165.37(dtm, J=255.2, 16.1 Hz), 164.19 (dddd, J=253.1, 14.5, 13.3, 10.6 Hz),109.28-108.33 (m), 101.11 (tm, J=25.1 Hz). ³¹P NMR (162 MHz, CDCl₃) δ37.34 (pt, J=43.1, 2.1 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −97.32 (dt,J=43.6, 9.0 Hz), −102.19 (pm, J=8.6 Hz).

Step 3. Preparation of bis(2,4,6-trifluorophenyl)iodophosphine

Iodotrimethylsilane (3.205 g, 16.02 mmol) was slowly added to a solutionof bis(2,4,6-trifluorophenyl)chlorophosphine (3.824 g, 11.64 mmol) inether (20 mL). The reaction mixture instantly turned deep yellow. A ³¹PNMR spectrum taken within 10 minutes of the addition showed the reactionwas complete. The volatiles were removed under reduced pressure. Theresidue was extracted with ether, filtered, and the volatiles wereremoved under reduced pressure to give an orange oil, 5.0782 g. Theresidue was extracted with a mixture of hexane and ether and filtered.The volatiles were removed under reduced pressure to give the product asan orange oil, 4.83 g, 98.8%. ¹H NMR (500 MHz, CDCl₃) δ 6.69 (dddm,J=8.7, 7.8, 2.0 Hz, 1H), ¹³C NMR (126 MHz, CDCl₃) δ 165.24 (dt, J=255.1,16.0 Hz), 165.29 (dddd, J=252.8, 15.2, 13.2, 10.4 Hz), 105.40 (dtm,J=58.2, 21.4 Hz). ³¹P NMR (202 MHz, CDCl₃) δ −31.87 (pt, J=36.4, 2.5Hz). ¹⁹F NMR (470 MHz, CDCl₃) δ −93.83 (dtm, J=36.5, 9.1 Hz), −102.58(pm, J=8.7 Hz).

Step 4. Preparation of(2S,5S)—N-(bis(2,4,6-trifluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L636

A solution of bis(2,4,6-trifluorophenyl)iodophosphine (0.446 g, 1.06mmol) in diethyl ether (6 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.328 g, 1.05 mmol) andtriethylamine (1.530 g, 15.13 mmol) in diethyl ether (6 mL) withformation of precipitate. The reaction mixture was stirred overnight.³¹P NMR spectroscopy showed the reaction to be complete. The reactionmixture was filtered, and the volatiles were removed under reducedpressure to give a pale yellow solid with small crystallites. The solidwas extracted with ether, filtered, and the volatiles were removed underreduced pressure to give the product as a solid. The residue wastriturated with hexanes, filtered, and the volatiles were removed underreduced pressure (overnight vacuum at 36° C.) to give the product as anoff-white solid, 0.5740 g, 90.30%. ¹H NMR (400 MHz, CDCl₃) δ 7.36-7.24(m, 7H), 7.20 (tq, J=7.1, 1.5 Hz, 1H), 7.02 (t, J=7.6 Hz, 2H), 6.92 (t,J=7.4 Hz, 1H), 6.63 (ddd, J=9.2, 7.9, 1.8 Hz, 2H), 6.39 (td, J=8.4, 2.1Hz, 2H), 4.00 (ddt, J=12.1, 8.2, 4.4 Hz, 1H), 3.52 (ddd, J=24.6, 13.5,5.5 Hz, 1H), 3.16-2.95 (m, 3H), 2.67 (dddd, J=15.5, 13.3, 7.7, 5.0 Hz,1H), 2.39 (tt, J=10.9, 5.3 Hz, 1H), 1.79 (qm, J=12.7 Hz, 1H), 0.82-0.70(m, 3H), 0.45 (t, J=7.1 Hz, 3H), ¹³C NMR (101 MHz, CDCl₃) δ165.72-164.88 (m), 164.47-163.62 (m), 163.16-162.41 (m), 161.97-161.08(m), 143.72, 143.51, 138.00 (d, J=2.5 Hz), 128.40, 128.30 (t, J=3.2 Hz),128.05, 127.96, 127.73, 125.80 (d, J=2.6 Hz), 125.48 (d, J=2.2 Hz),100.75 (ddd, J=30.9, 24.8, 3.4 Hz), 100.29 (ddd, J=30.8, 24.8, 3.0 Hz),58.62 (d, J=30.5 Hz), 55.70 (dd, J=22.3, 16.2 Hz), 51.76 (dd, J=21.2,7.7 Hz), 36.45 (d, J=1.9 Hz), 34.04 (d, J=7.3 Hz), 32.56 (dd, J=8.8, 3.8Hz), 19.65, 13.45. ³¹P NMR (162 MHz, CDCl₃) δ 108.88 (d, J=30.6 Hz),14.07 (h, J=39.0 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −98.36 (t, J=8.9 Hz),−98.47 (t, J=8.8 Hz), −100.72 (dt, J=38.6, 8.4 Hz), −105.13 (p, J=8.9Hz), −108.85 (pd, J=8.6, 2.2 Hz).

Preparation of(2S,5S)—N-(bis(2,4-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L638 Step 1. Preparation ofbis(2,4-difluorophenyl)dimethylaminophosphine

1-Bromo-2,4-difluorobenzene (19.469 g, 100.9 mmol) was added slowlydropwise to a chilled (−96 to −91° C. (liquid nitrogen/acetone))solution of n-butyllithium in hexanes (41.5 mL, 2.39 M, 99.19 mmoltotal) in ether (250 mL) such that the temperature did not exceed −88°C. The temperature was allowed to increase to between −78 and −74° C.for 1 hour (dry ice bath) with formation of white precipitate. Asolution of dimethylphosphoramidous dichloride (7.000 g, 47.96 mmol) inether (20 mL total) was added slowly dropwise at a rate such that thetemperature did not exceed −64° C. The reaction mixture was allowed towarm while stirring overnight. By morning the color was reddish-purple.The flask was taken into a glovebox. ³¹P NMR spectroscopy showed a majortriplet peak at 43.5 ppm (88%) from the desired product, a minor doubletpeak (presumed to be the monoaryl compound,dimethylamino(chloro)(2,4-difluorophenyl)phosphine) at 50.9 ppm (8.5%),and a small broad multiplet at about 36 ppm (3.5%). The volatiles wereremoved under reduced pressure to about 150 mL. Hexane (about 150 mL)was added and the mixture was filtered. The volatiles were removed underreduced pressure to give a deep red oil. The solid was extracted withhexane, filtered, and the volatiles were removed under reduced pressureovernight to give a deep red-purple oil. The oil was trap-to-traptransferred to give a pale yellow liquid. Much of the liquid wascolorless as it came over, but a small amount of splatter sent somecolor over, yield: 9.8384 g. The product contains 9.3% of the monoarylcompound and 90.7% desired bis(2,4-difluorophenyl)dimethylaminophosphinecompound. The distillate was partially distilled into two fractions:Distillate, 3.952 g, which contains 16.9% of the monoaryl compound and83.1% desired bis(2,4-difluorophenyl)dimethylaminophosphine compound,and pot residue, 5.633 g, 39.28%, which contains 2.7% of the monoarylcompound and 97.3% desired bis(2,4-difluorophenyl)dimethylaminophosphinecompound. ¹H NMR (500 MHz, CDCl₃) δ 7.07-6.99 (m, 1H), 6.73 (td, J=8.3,2.5 Hz, 1H), 6.64 (tdd, J=9.3, 3.4, 2.4 Hz, 1H), 2.49 (d, J=9.8 Hz, 3H),¹³C NMR (101 MHz, CDCl₃) δ 163.88 (dd, J=250.6, 11.9 Hz), 163.52 (ddd,J=247.2, 16.8, 11.8 Hz), 133.27 (dt, J=9.5, 7.4 Hz), 120.41 (dddd,J=22.1, 20.3, 3.7, 2.3 Hz), 111.55 (ddd, J=20.3, 3.4, 1.2 Hz), 103.76(dd, J=27.4, 25.2 Hz), 41.92 (d, J=17.4 Hz). ³¹P (162 MHz, CDCl₃) δ43.50 (tt, J=42.4, 3.5 Hz). ¹⁹F NMR (376 MHz, CDCl₃) δ −101.86 (dq,J=42.4, 8.9 Hz), −109.38 (pd, J=9.2, 8.7, 3.4 Hz). ³¹P NMR fordimethylamino(chloro)(2,4-difluorophenyl)phosphine (162 MHz, CDCl₃) δ50.87 (dd, J=26.4; 3.3 Hz).

Step 2. Preparation of bis(2,4-difluorophenyl)chlorophosphine

Anhydrous HCl in ether (55.0 mL, 2M, 110 mmol) was added to a solutionof bis(2,4-difluorophenyl)dimethylaminophosphine (8.00 g, 26.6 mmol) inmethylene chloride (50 mL) with substantial decolorizing of the deepreddish-brown reaction mixture to light orange. A ³¹P NMR spectrumshowed the reaction to be complete with about 10% of the putativedichloro(2,4-difluorophenyl)phosphine compound being present as well asthe desired product. The volatiles were removed under reduced pressure.The residue was extracted with a mixture of ether and hexanes (50/50)and filtered. The volatiles were removed under reduced pressure to givethe product as an orange oil. NMR spectra showed about 8% of putativedichloro(2,4-difluorophenyl)phosphine, 3% of another impurity, and 88%of bis(2,4-difluorophenyl)chlorophosphine. The oil was trap-to-trapvacuum transferred (hot water bath/liquid nitrogen) at 90° C. A smallamount of liquid distilled over which was enriched in thedichloro(2,4-difluorophenyl)phosphine impurity. The distillation wascontinued with use of a heat gun to increase the temperature to obtainthe product as a water-white liquid, 4.561 g, 58.69%, which containedabout 3.7% of putative 2,4-difluorophenylphosphine dichloride,identified by a doublet in the ³¹P NMR spectrum, δ 86.39 (d, J=54.9 Hz).¹H NMR (500 MHz, CDCl₃) δ 7.57 (tdd, J=8.3, 6.3, 5.3 Hz, 1H), 6.97 (td,J=8.3, 2.4 Hz, 1H), 6.82 (tdd, J=9.1, 3.5, 2.4 Hz, 1H). ¹³C NMR (126MHz, CDCl₃) δ 165.26 (dd, J=254.4, 12.2 Hz), 163.93 (ddd, J=250.8, 19.4,12.2 Hz), 134.21 (ddd, J=12.6, 9.9, 5.7 Hz), 119.92 (ddm, J=40.32, 16.4Hz), 112.34 (dt, J=21.0, 3.1 Hz), 104.34 (t, J=26.0 Hz). ³¹P NMR (202MHz, CDCl₃) δ 58.97 (tt, J=60.5, 2.9 Hz). ¹⁹F NMR (470 MHz, CDCl₃) δ−101.04 (dq, J=60.5, 9.4 Hz), −105.13 (pd, J=8.8, 2.6 Hz).

Step 3. Preparation of bis(2,4-difluorophenyl)iodophosphine

Iodotrimethylsilane (2.000 g, 9.99 mmol) was slowly added to a solutionof bis(2,4-difluorophenyl)chlorophosphine (2.000 g, 6.84 mmol) in ether(10 mL). The reaction mixture instantly turned deep yellow. A ³¹P NMRspectrum taken within 10 minutes of the addition showed the reaction wascomplete. The volatiles were removed under reduced pressure to give ayellow oil. Yield was 2.543 g, 96.88%. ¹H NMR (500 MHz, CDCl₃) δ 7.55(tdd, J=8.4, 6.4, 4.6 Hz, 1H), 6.93 (td, J=8.3, 2.5 Hz, 1H), 6.82 (dddd,J=9.5, 8.7, 3.6, 2.4 Hz, 1H), 13C NMR (126 MHz, CDCl₃) δ 165.42 (dd,J=254.7, 12.0 Hz), 163.56 (ddd, J=251.2, 19.3, 12.3 Hz), 137.63 (td,J=10.4.4.8 Hz), 116.22 (dddd, J=46.3, 17.4, 4.1, 1.8 Hz), 112.50 (ddd,J=21.0, 3.6, 2.1 Hz), 104.33 (dd, J=26.7, 25.3 Hz). ³¹P NMR (202 MHz,CDCl₃) δ 8.27 (tt, J=59.5, 2.0 Hz). ¹⁹F NMR (470 MHz, CDCl₃) δ −97.05(dq, J=59.7, 9.6 Hz), −105.12 (p, J=8.7 Hz).

Step 4. Preparation of(2S,5S)—N-(bis(2,4-difluorophenyl)phosphanyl)-N-butyl-2,5-diphenylphospholan-1-amine,L638

A solution of bis(2,4-difluorophenyl)iodophosphine (0.490 g, 1.28 mmol)in diethyl ether (6 mL) was added slowly to a solution ofN-butyl-2,5-diphenylphospholan-1-amine (0.394 g, 1.27 mmol) andtriethylamine (1.64 g, 16.2 mmol) in diethyl ether (6 mL) with formationof precipitate. The reaction mixture was stirred overnight. ³¹P NMRspectra showed the reaction to be complete. The reaction mixture wasfiltered, and the volatiles were removed under reduced pressure to givea pale yellow solid with small crystallites. The solid was extractedwith ether, filtered, and the volatiles were removed under reducedpressure. The solid residue was triturated with hexanes, filtered,washed with hexane, and the volatiles were removed under reducedpressure to give the product as colorless powder, 0.5106 g, 71.11%. ¹HNMR (500 MHz, CDCl₃) δ 7.37-7.28 (m, 7H), 7.22 (ddq, J=7.5, 6.4, 1.6 Hz,1H), 7.10 (tm, J=7.4 Hz, 2H), 7.07-7.00 (m, 1H), 6.90-6.82 (m, 1H), 6.79(tm, 9.1 Hz, 1H), 6.70-6.60 (m, 2H), 6.54 (td, J=8.4, 2.4 Hz, 1H), 6.44(qd, J=7.9, 4.5 Hz, 1H), 4.06 (ddd, J=12.1, 7.8, 4.1 Hz, 1H), 3.46 (ddd,J=23.7, 13.5, 5.7 Hz, 1H), 3.04-2.86 (m, 4H), 2.74-2.61 (m, 1H), 2.38(tt, J=10.8, 5.3 Hz, 1H), 1.78 (qd, J=12.9, 5.0 Hz, 1H), 0.94-0.82 (m,III), 0.76 (tt, J=14.2, 7.2 Hz, 2H), 0.48 (t, J=7.3 Hz, 4H), ¹³C NMR(126 MHz, CDCl₃) δ 164.27 (dd, J=252.0, 12.2 Hz), 164.06 (ddd, J=247.8,19.2, 11.9 Hz), 163.35 (dd, J=250.0, 11.9 Hz), 162.09 (ddd, J=247.0,17.4, 11.9 Hz), 143.76 (d, J=20.6 Hz), 138.34 (d, J=2.3 Hz), 133.89 (tt,J=12.3, 6.8 Hz), 128.46, 128.35 (dd, J=3.7, 1.8 Hz), 128.13, 128.08,128.01, 125.78 (dd, J=11.4, 2.3 Hz), 121.44 (ddd, J=26.3, 18.8, 3.2 Hz),120.54 (ddt, J=22.1, 18.9, 3.0 Hz), 111.51 (dd, J=7.1, 3.3 Hz), 111.35(dd, J=7.4, 3.3 Hz), 103.87 (dd, J=27.9, 24.8 Hz), 103.27 (dd, J=27.2,24.9 Hz), 54.64, 54.43, 51.84 (dd, J=21.9, 4.6 Hz), 36.48 (d, J=1.8 Hz),33.83 (dd, J=6.7, 2.1 Hz), 32.62 (dd, J=7.6, 3.4 Hz), 19.63, 13.48. ³¹PNMR (162 MHz, CDCl₃) δ 102.16, 31.55 (ddd, J=53.8, 41.6, 22.0 Hz). ¹⁹FNMR (376 MHz, CDCl₃) δ −100.50 (dq, J=41.6, 9.0 Hz), −100.97 (dq,J=53.9, 9.3 Hz), −108.02 (t, J=8.9 Hz), −110.30 (t, J=9.0 Hz).

Preparation ofrac-N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(4-methylphenyl)phospholan-1-amine,L645 Step 1. Preparation of 4-methylphenylmagnesium bromide in THF

A two-necked flask, equipped with a stir bar and a Stevens (spiraltube-type) condenser, was charged with magnesium turnings (7.46 g, 306.9mmol) and 100 mL of THF. Two drops of 1,2 dibromoethane were added tothe resulting mixture. The mixture was allowed to stir for 5 min toactivate the magnesium turnings. In a separate container, 4-bromotoluene(50.00 g, 321.6 mmol) was diluted with 60 mL of THF and drawn into asyringe. With a fan circulating air over the condenser, the solution of4-bromotoluene was carefully added in 5- or 10-mL portions, allowing themixture to stir for a few minutes between additions until the refluxingstopped. The container previously containing the solution of4-bromotoluene was rinsed with 162 mL of THF, the rinse solvent wasdrawn with the same syringe used earlier and added to the reactionmixture. The Grignard solution that resulted was filtered through adisposable plastic fritted funnel to remove excess magnesium andtitrated using salicylaldehyde phenylhydrazone to confirm aconcentration of 1.0 M. The Grignard solution was used as-is insubsequent reactions.

Step 2. Preparation of (E,E)-1,4-bis(4-methylphenyl)-1,3-butadiene

(E,E)-1,4-Bis-(4-methylphenyl)-1,3-butadiene was prepared according to aprocedure adapted from Hintermann et al. (Hintermann, L.; Schmitz, M.;Chen, Y. Adv. Synth. Catal. 2010, 352, 2411). A 1-L three-necked,oven-dried flask was charged with toluene (300 mL), nickel (II)acetylacetonate, (Ni(acac)₂), (1.02 g, 3.98 mmol, 3 mol %) and1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride (3.38 g, 9.96 mmol,7.5 mol %). While stirring, thiophene (12.8 mL, 159.4 mmol) and the4-methylphenylmagnesium bromide solution (1.0 M, 321.6 mL, 321.6 mmol)were added sequentially to the reaction mixture. The reaction mixturewas heated to 80° C. and stirred overnight, then monitored by NMRspectroscopy. Upon completion of the reaction, the reaction mixture wascooled (with an ice bath), diluted with 2-4 volumes of toluene, andquenched by careful addition of an equal volume of saturated aqueousNH₄Cl (caution H₂S gas is generated). The organic phase was washed withequal volumes of HCl (2.4 M), NaOH (2 M), and water and was then driedover anhydrous MgSO₄. The solution was then filtered through a silicagel plug. The plug was rinsed several times with dichloromethane.Solvent was removed on a rotary evaporator, the solid was trituratedwith pentane, collected on a fritted plastic filter, and dried underreduced pressure. The solid was analyzed by X-ray fluorescencespectroscopy (XFS) and determined to contain approximately 4% sulfur.The sample was passed through basic alumina using dichloromethane as theeluent, dried under vacuum, and analyzed by XFS: minimal reduction insulfur content was observed. Four separate 100 mg samples were dissolvedin dichloromethane and three solutions were each treated with H₂O₂(dilute in H₂O), NaOCl (dilute in H₂O), or Na₂S₂O₃ (solid). Theremaining sample, the control, was not treated. The samples were stirredovernight, separated from the aqueous layer (when applicable), filteredthrough basic alumina, dried under vacuum, and then analyzed by XFS. Allsamples, except for the control, showed a significant reduction insulfur. The bulk of the material was purified with sodium thiosulfateand basic alumina, and then used as-is in subsequent steps (Yield: 15.3g, 49%). ¹H NMR (400 MHz, CDCl₃) δ 7.40-7.31 (m, 2H), 7.15 (d, J=7.8 Hz,2H), 6.98-6.86 (m, 1H), 6.69-6.58 (m, 1H), 2.36 (s, 3H). ¹³C NMR (100MHz, CDCl₃): δ=137.3, 134.6, 132.2, 129.3, 128.4, 126.2, 21.4.

Step 3. Preparation of(1S,2S,5R)-1-(dimethylamino)-2,5-bis(4-methylphenyl)-2,5-dihydrophosphole1-oxide

In a reaction not carried out in a glovebox, dimethylphosphoramidousdichloride (3.60 g, 31.3 mmol) was added to a stirred suspension ofaluminum chloride (3.95 g, 29.6 mmol) in dichloromethane (50 mL) in alarge jacketed multi-neck flask purged with nitrogen. After 45 min, theresulting greenish solution and a solution of(E,E)-1,4-bis(4-methylphenyl)-1,3-butadiene (6.70 g, 28.6 mmol) indichloromethane (125 mL) were each cooled to 0° C. After cooling, the(E,E)-1,4-bis(4-methylphenyl)-1,3-butadiene solution was slowly added tothe dimethylphosphoramidous dichloride-aluminum chloride solution. Themixture was allowed to stir overnight at 0° C. A solution of aqueousEDTA (ethylenedi amine tetraacetic acid, 0.2 M, 200 mL) and saturatedNaHCO₃ (100 mL) cooled in ice water was then added to the reactionmixture. The mixture was stirred at 0° C. for 4 h, filtered throughCelite, decanted, and the aqueous layer was extracted withdichloromethane. The organic layers were washed with NaHCO₃, 1 M HCl,brine, and dried over anhydrous MgSO₄. The solution was concentrated ona rotary evaporator and the resulting yellow oil was triturated withdiethyl ether to yield a pale yellow solid (Yield: 7.5 g, 81%). ¹H NMR(400 MHz, C₆D₆) δ 7.20 (dd, J=8.2, 2.2 Hz, 4H), 6.95 (d, J=7.8 Hz, 4H),6.11 (d, J=27.9 Hz, 2H), 4.21 (d, J=18.2 Hz, 2H), 2.09 (s, 6H), 1.91 (s,3H), 1.89 (s, 4H), ¹³C NMR (101 MHz, C₆D₆) δ 136.04 (d, 2.6 Hz), 133.63(d, J=8.3 Hz), 130.75 (d, J=16.0 Hz), 129.33 (d, J=2.3 Hz), 127.27 (d,J=4.7 Hz), 49.08 (d, 70.8 Hz), 36.21, 36.20, 21.04. ³¹P NMR (162 MHz,C₆D₆) δ 66.68.

Step 4. Preparation of rac-1-(dimethylamino)-2,5-bis(4-methylphenyl)phospholane 1-oxide

In a reaction not earned out in a glovebox, a pressure reactor wascharged with(1S,2S,5R)-1-(dimethylamino)-2,5-bis(4-methylphenyl)-2,5-dihydrophosphole1-oxide (6.69 g, 20.6 mmol), 10% Pd/C (438 mg, 0.41 mmol), sodiumcarbonate (1.09 g, 10.28 mmol), and methanol (100 mL). The reactor waspurged with hydrogen, and then pressurized to 500 psi of hydrogen. After2.5 h, an aliquot was taken and analyzed by NMR spectroscopy, confirmingcomplete hydrogenation. The reaction mixture was filtered throughCelite, and then heated to 40° C. for 1 hr and 40 min under anatmosphere of nitrogen. An aliquot was analyzed by NMR spectroscopy,confirming incomplete isomerization. Additional sodium carbonate wasadded (150 mg) and the reaction mixture was allowed to react overnightat room temperature; no change was observed by NMR spectroscopy. Thereaction mixture was heated for 2.5 hr, and an aliquot was taken,confirming complete conversion. The solvent was removed under vacuum andthe solid was treated with water. The product was then extracted withdichloromethane using a separatory funnel. The solution was dried usinganhydrous MgSO₄, then filtered through Celite. The solvent was removedunder vacuum. The solid was triturated with a few milliliters of acetonefor 2 min, and the undissolved solid was isolated using a disposableflitted funnel. The white powder was dried under vacuum (Yield: 4.02 g,59.7%). ¹H NMR (400 MHz, CDCl₃) δ 7.26-7.18 (m, 4H), 7.14 (d, J=7.9 Hz,4H), 3.57 (ddd, J=23.4, 12.4, 7.7 Hz, 1H), 3.24 (td, J=12.9, 7.1 Hz,1H), 2.57-2.41 (m, 1H), 2.46-2.35 (m, 1H), 2.34 (s, 3H), 2.33 (s, 3H),2.31 (s, 3H), 2.31 (s, 3H), 2.31-2.14 (m, 1H), 2.07 (qdd, J=12.9, 5.0,2.2 Hz, 1H). ¹³C NMR (101 MHz, CDCl₃) δ 136.40 (d, J=2.4 Hz), 136.12 (d,J=2.8 Hz), 134.13 (d, J=4.7 Hz), 133.37 (d, J=5.4 Hz), 129.41 (d, J=2.0Hz), 129.22 (d, J=2.2 Hz), 128.75 (d, J=5.1 Hz), 127.24 (d, J=5.0 Hz),46.97 (d, J=75.8 Hz), 42.21 (d, J=77.9 Hz), 36.14, 36.12, 29.97 (d,J=12.1 Hz), 27.86 (d, J=9.5 Hz), 21.17 (d, J=3.0 Hz). ³¹P NMR (162 MHz,CDCl₃) δ 59.51.

Step 5. Preparation of rac-1-chloro-2,5-bis(4-methylphenyl)phospholane

An oven-dried vial was charged with rac-1-(dimethylamino)-2,5-bis(4-methylphenyl)phospholane-1-oxide (1.50 g, 4.60 mmol)mixed in ether (total reaction volume of 30 mL). Pyridine (0.410 mL,5.06 mmol) and trichlorosilane (0.511 mL, 5.06 mmol) were addedsequentially, and the mixture was stirred overnight (approximately 18hr) at room temperature. Pentane (10 mL) was added to the resultingslurry and it was filtered through a disposable fritted filter. Thefiltrate was then concentrated to dryness. The solid was dissolved inpentane (20 mL) and passed through a plug of acidic alumina. The aluminawas rinsed with another 20 mL of pentane. The filtrate was thenconcentrated and placed in the freezer at −35° C. Overnight, aprecipitate was formed which was then isolated via filtration. Theresulting white solid was dried under vacuum (Yield: 601 mg, 43%). ¹HNMR (400 MHz, C₆D₆) δ 7.19 (d, J=7.7 Hz, 2H), 7.02 (d, J=7.9 Hz, 2H),6.98 (s, 4H), 3.80 (td, J=8.7, 2.2 Hz, 1H), 3.17 (ddd, J=33.6, 12.4, 5.8Hz, 1H), 2.55-2.39 (m, 1H), 2.43-2.29 (m, 1H), 2.13 (s, 6H), 2.07 (dddd,J=13.2, 9.3, 5.8, 1.8 Hz, 1H), 1.71-1.54 (m, 1H). ¹³C NMR (101 MHz,C₆D₆) δ 139.06 (d, J=19.4 Hz), 136.23 (d, J=3.1 Hz), 136.17 (d, J=2.0Hz), 134.19, 129.82, 129.36, 128.53, 128.49, 57.83 (d, J=31.8 Hz), 53.36(d, J=32.6 Hz), 34.69 (d, J=2.6 Hz), 32.11 (d, J=3.3 Hz), 21.07, 21.02.³¹P NMR (162 MHz, C₆D₆) δ 137.01.

Step 6. Preparation ofrac-N-butyl-2,5-bis(4-methylphenyl)phospholan-1-amine

A solution of rac-1-chloro-2,5-bis(4-methylphenyl)phospholane (601 mg,1.98 mmol) in pentane (30 mL) was treated with n-butylamine (1.45 g,19.8 mmol) in 5 mL of pentane. After stirring for 30 min, an aliquot wasremoved for NMR analysis which confirmed complete conversion. Theresulting slurry was filtered through a plug of neutral alumina. Thealumina was rinsed with an additional 10 mL of pentane. The filtrate wasconcentrated under vacuum to yield the product as a colorless oil. Theoil was dissolved in a small amount of pentane and placed in the freezerat −35° C. After a few hours, a precipitate was formed. The white powderwas isolated, by filtration and dried under vacuum (Yield: 550 mg, 82%).¹H NMR (400 MHz, C₆D₆) δ 7.31 (dd, J=8.1, 1.8 Hz, 2H), 7.15-7.02 (m,7H), 3.09 (ddd, J=22.0, 12.5, 6.0 Hz, 1H), 2.95 (dt, J=12.6, 6.7 Hz,1H), 2.60-2.40 (m, 1H), 2.37-2.23 (m, 1H), 2.19 (s, 3H), 2.17 (s, 3H),2.15-2.05 (m, 1H), 1.85 (qdd, J=12.5, 5.1, 2.6 Hz, 1H), 1.62 (qdd,J=12.6, 5.1, 2.5 Hz, 1H), 1.08-0.98 (m, 1H), 1.01-0.87 (m, 4H), 0.68 (t,J=6.9 Hz, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 141.47 (d, J=18.3 Hz), 137.32,135.13 (d, J=2.6 Hz), 134.77 (d, J=2.4 Hz), 129.50-129.45 (d, J=5 Hz),129.27-129.20 (d, J=5 Hz), 128.22 (d, J=3.4 Hz), 127.97, 55.67 (d,J=14.3 Hz), 50.04 (d, J=22.6 Hz), 47.88 (d, J=23.1 Hz), 35.59 (d, J=6.8Hz), 34.43 (d, J=2.8 Hz), 31.95 (d, J=2.1 Hz), 21.08, 20.06, 14.01. ³¹PNMR (162 MHz, C₆D₆) δ 72.29.

Step 7. Preparation ofrac-N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(4-methylphenyl)phospholan-1-amine,L645

A cold (−30° C.) solution of bis(2-fluorophenyl)iodophosphine (200 mg,0.574 mmol) in pentane (10 mL) was added to a cold (−30° C.) solution ofrac-N-butyl-2,5-bis(4-methylphenyl)phospholan-1-amine (195 mg, 0.574mmol) and triethylamine (64 mg, 0.631 mmol) in pentane (20 mL), causingimmediate formation of precipitate. After 1 hr, an aliquot was analyzedby ³¹P NMR which showed complete conversion to the desired product. Thereaction mixture was filtered through a small neutral alumina plug,additional pentane was used to wash the alumina, and the solvent wasremoved under vacuum. A small quantity of pentane was added and a whitepowder began to precipitate. The material was placed in the freezer at−35° C. for several days. The solution was decanted, and the resultingsolid was dried under vacuum. A small sample was taken and analyzed byNMR spectroscopy: 2%rac-N-butyl-2,5-bis(4-methylphenyl)phospholan-1-amine was observed. Thesolid was stirred in pentane, the solution was decanted, and the solidwas dried under vacuum. NMR spectroscopy confirmed the absence ofstarting material (Yield: 230 mg, 72%). ¹H NMR (400 MHz, C₆D₆) δ 7.41(dd, J=8.0, 1.7 Hz, 2H), 7.31 (d, J=7.7 Hz, 2H), 7.10 (d, J=7.7 Hz, 2H),7.09-6.99 (m, 1H), 6.85 (dddd, J=9.7, 7.8, 5.0, 2.1 Hz, 2H), 6.79 (d,J=7.9 Hz, 2H), 6.75 (ddd, J=8.4, 4.2, 1.3 Hz, 1H), 6.72-6.56 (m, 4H),4.42 (ddt, J=12.2, 8.3, 4.4 Hz, 1H), 3.33 (ddd, J=24.2, 13.5, 5.4 Hz,1H), 3.21-2.99 (m, 3H), 2.69-2.52 (m, 1H), 2.17 (s, 3H), 2.15-2.10 (m,1H), 2.08 (s, 3H), 1.64 (qd, J=12.8, 4.8 Hz, 1H), 1.13 (ddt, J=16.5,13.7, 7.1 Hz, 1H), 0.70-0.47 (m, 3H), 0.36 (t, J=7.2 Hz, 3H), ¹³C NMR(101 MHz, C₆D₆) δ 166.40-163.73 (m), 163.80-161.28 (m), 141.94, 135.94(d, J=2.3 Hz), 135.20 (d, J=2.6 Hz), 134.83 (d, J=2.1 Hz), 133.81-133.45(m), 131.72 (d, J=8.6 Hz), 129.61, 129.50, 129.23, 128.88-128.76 (m),128.68 (d, J=8.6 Hz), 126.76 (dd, J=27.2, 18.7 Hz), 126.29 (dd, J=19.0,2.6 Hz), 126.06 (dd, J=18.8, 2.4 Hz), 124.31 (d, J=3.3 Hz), 124.14 (d,J=3.2 Hz), 115.58 (d, J=24.2 Hz), 114.75 (d, J=23.0 Hz), 55.27 (dd,J=31.6, 4.6 Hz), 55.49 (dd, J=13.5, 3.8 Hz), 55.38-55.16 (m), 52.09 (dd,J=21.6, 5.2 Hz), 37.20, 34.35 (d, J=7.4 Hz), 33.00 (dd, J=8.7, 3.5 Hz),21.11 (d, J=3.0 Hz), 20.00, 13.69. ³¹P NMR (162 MHz, C₆D₆) δ 102.13 (d,J=30.8 Hz), 31.82 (ddd, J=57.1, 42.1, 30.5 Hz). ¹⁹F NMR (376 MHz, C₆D₆)δ −103.50 (ddt, J=41.9, 10.4, 6.0 Hz), −104.52 (dq, J=57.1, 7.1 Hz).

Preparation ofrac-N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(3,5-dimethylphenyl)phospholan-1-amine, L647 Step 1. Preparation ofrac-N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(3,5-dimethylphenyl)phospholan-1-amine, L647

A cold (−30° C.) solution of bis(2-fluorophenyl)iodophosphine (100 mg,0.288 mmol) in pentane (10 mL) was added dropwise to a cold (−30° C.)solution of rac-N-butyl-2,5-bis(3,5-dimethylphenyl)phospholan-1-amine(106 mg, 0.288 mmol) and triethylamine in pentane (20 mL), causingimmediate solid formation. After 30 min, an aliquot was analyzed by³¹P-NMR which confirmed complete conversion to the desired product. Thereaction mixture was filtered through a small alumina plug and thesolvent was removed under vacuum. The residue was extracted withpentane, the resulting solution was filtered through Celite, and placedin the freezer. White crystals formed overnight. The solution wasdecanted, and the resulting solid was dried under vacuum (Yield: 65 mg,38%). ¹H NMR (400 MHz, C₆D₆) δ 7.14 (d, J=3.3 Hz, 4H), 7.14-7.06 (m,1H), 6.92-6.80 (m, 2H), 6.83-6.74 (m, 2H), 6.74-6.60 (m, 4H), 6.53 (s,1H), 4.37 (ddt, J=12.3, 8.4, 4.5 Hz, 1H), 3.38 (ddd, J=23.7, 13.5, 5.3Hz, 1H), 3.29-3.02 (m, 2H), 2.73-2.56 (m, 1H), 2.24 (s, 6H), 2.07 (s,6H), 1.72 (qd, J=12.6, 4.9 Hz, 1H), 1.04 (tdd, J=13.5, 7.5, 3.7 Hz, 1H),0.69-0.48 (m, 3H), 0.38 (t, J=7.1 Hz, 3H), ¹³C NMR (101 MHz, C₆D₆) δ166.27-163.84 (m), 163.84-161.19 (m), 144.71 (d, J=20.6 Hz), 138.89 (d,J=2.2 Hz), 137.94-137.74 (m), 137.70-137.50 (m), 133.68 (t, J=5.2 Hz),133.50 (dd, J=8.3, 5.2 Hz), 131.65 (d, J=8.4 Hz), 130.05 (d, J=8.2 Hz),128.70, 127.72, 127.71, 127.10-126.84 (m), 126.70 (d, J=8.4 Hz),126.60-125.98 (m), 124.28 (d, J=3.2 Hz), 124.09 (d, J=3.2 Hz), 115.56(d, J=23.9 Hz), 114.69 (d, J=23.1 Hz), 55.89-55.41 (m), 55.39 (dd,J=32.3, 5.2 Hz), 52.67 (dd, J=22.1, 4.6 Hz), 36.81, 34.63 (d, J=7.2 Hz),32.95 (dd, J=8.5, 3.5 Hz), 21.53, 21.39, 20.01, 13.80. ³¹P NMR (162 MHz,C₆D₆) δ 103.43 (d, J=31.1 Hz), 32.16 (ddd, J=55.9, 38.8, 31.4 Hz).¹⁹F{¹H} NMR (376 MHz, C₆D₆) δ −103.26 (d, J=38.7 Hz), −104.27 (d, 7-55.6Hz). ¹⁹F NMR (376 MHz, C₆D₆) δ −103.26 (ddt, J=38.4, 9.5, 5.7 Hz),−104.27 (dq, J=55.4, 7.3 Hz).

Preparation ofrac-(2S,5S)—N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(4-(tert-butyl)phenyl)phospholan-1-amine,L648 Step 1. Preparation of 1,4-bis(4-tert-butylphenyl)-1,3-butadiene

Toluene (100 mL) was added to a round-bottomed flask containingNi(acetylacetonate)₂ (0.193 g, 0.75 mmol, 3 mol %) and1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride (0.639 g, 1.87 mmol,7.5 mol %). The toluene mixture was stirred while thiophene (2.0 mL) and4-tert-butylphenylmagnesium bromide (57.5 mL, 57.5 mmol, 1.0 M) wereadded sequentially. The reaction vessel was heated to 80° C. Thereaction was monitored by GC/MS. Upon completion, the reaction mixturewas cooled, diluted with 4 volumes of toluene, and quenched by carefuladdition of an equal volume of saturated aqueous NH₄Cl (caution H₂S gasis generated). The organic phase was washed with equal volumes of HCl(2.4 M), NaOH (2 M), and water and was then dried over anhydrous MgSO₄.The solution was filtered and concentrated on a rotary evaporator.Initial attempts at purification by recrystallization from hexane wereunsuccessful. The material was purified by column chromatography onsilica eluting with a mixture of hexane and ethyl acetate (25%). Twofractions were collected and the volatiles were removed under reducedpressure. Fraction 1 (4.2 g) contained a mixture of the desired product(68%) and the homocoupled product, 4,4′-di-tert-butyl-biphenyl (32%).Fraction 2 (1.1 g) contained the desired trans-trans diene product andan impurity which we tentatively assigned as the cis-trans or cis-cisisomers of the product. Total yield of the desired material from the twofractions was approximately 4 g (50% yield). These fractions werecombined and used in the subsequent step without further purification.¹H NMR (400 MHz, CDCl₃) δ: 7.41-7.32 (m, 8H), 6.98-6.85 (m, 2H),6.71-6.57 (m, 2H), 1.32 (s, 18H), ¹³C NMR (101 MHz, CDCl₃) δ: 150.61,134.72, 132.15, 128.76, 126.06, 125.58, 34.62, 31.29.

Step 2. Preparation ofroc-(1S,2R,5S)-2,5-bis(4-tert-butylphenyl)-1-(dimethylamino)-2,5-dihydrophosphole-1-oxide

In a reaction not carried out in a glovebox, dimethylphosphoramidousdichloride (4.78 mL, 41.6 mmol) was added to a stirred suspension ofaluminum chloride (5.25 g, 39.6 mmol) in dichloromethane (50 mL) in alarge jacketed multi-neck flask purged with nitrogen. After 45 min, theresulting greenish solution and a solution of1,4-bis(4-t-butylphenyl)butadiene (12.1 g, 38.0 mmol) in dichloromethane(125 mL) were both cooled to 0° C. After cooling, the1,4-bis(4-t-butylphenyl)butadiene solution was slowly added to thedimethylphosphoramidous dichloride-aluminum chloride solution. Themixture was allowed to stir overnight at 0° C. A solution of aqueousEDTA (ethylenediamine tetraacetic acid, 0.2 M, 200 mL) and saturatedNaHCO₃ (100 mL) cooled in ice water was then added to the reactionmixture. The mixture was stirred at 0° C. for 4 h, filtered throughCelite, decanted, and the aqueous layer was extracted withdichloromethane. The organic layers were washed with NaHCO₃ (100 mL), 1MHCl (100 mL), brine (100 mL), and dried over anhydrous MgSO₄. Thesolution was concentrated on a rotary evaporator and the resultingyellow oil was triturated with ether to yield a white solid (6 g, 38%).A second crop was obtained from the washings (4.3 g, 27%) (total yield:10.3 g, 65%). ¹H NMR (400 MHz, CDCl₃) δ: 7.33 (d, J=8.3 Hz, 4H), 7.24(dd, J=8.5, 2.2 Hz, 4H), 6.51 (d, J=29.3 Hz, 2H), 4.26 (d, J=18.7 Hz,2H), 1.88 (d, J=8.3 Hz, 6H), 1.29 (s, 18H), ¹³C NMR (101 MHz, CDCl₃) δ:149.78, 149.75, 132.76, 132.68, 130.75 (d, ²J_(C-P)=17.0 Hz), 126.81,126.76, 125.31, 125.28, 48.83 (d, 71.9 Hz), 35.89 (d, ²J_(C-N-P)=2.0Hz), 34.45, 31.36. ³¹P NMR (162 MHz, CDCl₃) δ: 67.72 (ddp, J=45.6, 25.4,9.7, 9.2 Hz).

Step 3. Preparation ofrac-(1S,2R,5S)-2,5-bis(4-t-butylphenyl)-1-(dimethylamino)phospholane-1-oxide

In a reaction not carried out in a glovebox, a pressure reactor wascharged withrac-(1S,2R,5S)-2,5-bis(4-t-butylphenyl)-1-(dimethylamino)-2,5-dihydrophosphole-1-oxide(2) (2.5 g, 6.1 mmol), 10% Pd on carbon (0.065 g, 0.06 mmol), sodiumcarbonate (0.32 g, 3.05 mmol), and methanol (100 mL). The reactor waspurged with hydrogen, then pressurized to 500 psi with hydrogen. After 5h, the reaction mixture was filtered through Celite and the solvent wasremoved in vacuo to yield a colorless oil, which crystallized uponaddition of ether (1.24 g, 49%). ¹H NMR (400 MHz, CDCl₃) δ: 7.30 (d,J=8.4 Hz, 4H), 7.26-7.21 (m, 4H), 3.69-3.62 (m, 1H), 3.62-3.55 (m, 1H),2.63-2.41 (m, 3H), 1.83 (d, J=8.2 Hz, 6H), 1.28 (s, 18H). ³¹P NMR (162MHz, CDCl₃) δ: 66.56. ¹³C NMR (101 MHz, CDCl₃) δ:149.34, 149.31, 133.86,133.81, 126.65, 126.60, 125.16, 125.14, 45.22 (d, ¹J_(C-P)=72.7 Hz),35.28 (d, ²J_(C-N-P)=2.4 Hz), 34.37, 31.35, 26.78 (d, ²J_(C-P)=13.3 Hz).

Step 4. Preparation ofrac-(1S,2S,5S)-2,5-bis(4-tert-butylphenyl)-1-(dimethylamino)phospholane-1-oxide

A solution of sodium methoxide (0.33 g, 6.1 mmol) in methanol (20 mL)was added to a vial containing(1S,2R,5S)-2,5-bis(4-tert-butylphenyl)-1-(dimethylamino)phospholane1-oxide (3) (1.25 g, 3.03 mmol) and a magnetic stir bar. The reactionmixture was stirred for 5 hour's and placed in the freezer overnight at−35° C. The following morning the vial was taken out of the freezer andallowed to warm to room temperature, after which point a second additionof sodium methoxide (0.16 g, 3.0 mmol) was made and the reaction mixturewas stirred for an additional 6 hours. The solution was then poured intoa separatory funnel containing toluene (100 mL) and 1 M HCl (100 mL).The combined organic layer was washed sequentially with the HClsolution, water, brine, and dried over anhydrous MgSO₄. After filtrationthe volatiles were removed on a rotary evaporator and the white solidobtained was recrystallized from hot acetone (˜40 mL) to yield theproduct as a white solid (0.9 g, 72%). ¹H NMR (400 MHz, CDCl₃) δ: 7.36(dd, J=8.3, 3.5 Hz, 4H), 7.27 (dt, J=8.3, 1.8 Hz, 4H), 3.59 (ddd,J=23.2, 12.3, 7.8 Hz, 1H), 3.26 (td, J=12.8, 7.1 Hz, 1H), 2.57-2.46 (m,1H), 2.46-2.38 (m, 1H), 2.31 (d, J=8.8 Hz, 6H), 2.28-2.16 (m, 1H), 2.10(qdd, J=12.6, 4.9, 2.2 Hz, 1H), 1.32 (s, 9H), 1.30 (s, 9H), ¹³C NMR (101MHz, CDCl₃) δ: 149.55, 149.52, 149.31, 149.28, 134.08, 134.03, 133.27,133.21, 128.47, 128.42, 126.97, 126.92, 125.54, 125.52, 125.25, 125.23,46.90 (d, ¹J_(C-P)=75.8 Hz), 41.91 (d, ¹J_(C-P)=78.1 Hz), 36.06, 36.04,34.44, 34.41, 31.39, 31.36, 30.03 (d, ²J_(C-P)=12.3 Hz), 27.68 (d,²J_(C-P)=9.5 Hz). ³¹P NMR (162 MHz, CDCl₃) δ: 58.87 (m).

Step 5. Preparation ofrac-(2S,5S)-2,5-bis(4-tert-butylphenyl)-1-chlorophospholane

Pyridine (0.74 mL, 9.0 mmol) and trichlorosilane (0.93 mL, 0.89 mmol)were added to a solution ofrac-(1S,2S,5S)-2,5-bis(4-tert-butylphenyl)-1-(dimethylamino)phospholane-1-oxide(3.43 g, 8.31 mmol) in ether (80 mL). After stirring overnight, pentane(10 mL) was added to the reaction mixture which was filtered through adisposable fritted filter. The filtrate was concentrated to drynessunder reduced pressure to yield a white solid. The white solid wassuspended in pentane (20 mL) and placed in the freezer glovebox freezerat −35° C. overnight. The mixture was filtered and the white solid wasrinsed sparingly with cold pentane. The white solid was then transferredto a vial and dried under reduced pressure. A second crop was isolatedby concentration of the pentane washings followed by cooling in theglovebox freezer to yield a white solid which was isolated byfiltration, washed sparingly with cold pentane, and dried under reducedpressure. The combined yield of the two crops was 3.0 g (93%). ¹H NMR(400 MHz, C₆D₆) δ: 7.30 (d, J=2.3 Hz, 4H), 7.27 (d, J=8.2 Hz, 2H),7.09-7.02 (m, 2H), 3.86 (td, J=8.6, 2.2 Hz, 1H), 3.35-3.14 (m, 1H), 2.54(ddd, J=11.3, 7.2, 3.3 Hz, 1H), 2.42 (dq, J=15.7, 8.1 Hz, 1H), 2.14 (pd,J=10.7, 8.8, 5.3 Hz, 1H), 1.81-1.63 (m, 1H), 1.24 (d, J=2.0 Hz, 18H).¹³C NMR (101 MHz, C₆D₆) δ: 149.50, 139.10, 138.91, 134.24, 128.41,127.94, 126.07, 125.57, 57.94, 57.62, 53.49, 53.16, 34.66, 34.48, 32.34,32.30, 31.49. ³¹P NMR (162 MHz, C₆D₆) δ: 135.93

Step 6. Preparation ofrac-(2S,5S)—N-butyl-2,5-bis(4-tert-butylphenyl)phospholan-1-amine

A solution ofrac-(2S,5S)-2,5-bis(4-tert-butylphenyl)-1-chlorophospholane (1.0 g, 2.58mmol) in hexane (45 mL) was added to n-butylamine (2.6 mL, 25.8 mmol) inhexane (45 mL). After stirring for 30 minutes, the resulting slurry wasfiltered through a plug of neutral alumina. The alumina was rinsed withan additional 45 mL of hexane. The filtrate was concentrated undervacuum to yield the product as an oily white solid. Repeated rinsing ofthe white residue with cold pentane yielded the product as a white solidupon drying (1.04 g, 95%). ¹H NMR (400 MHz, C₆D₆) δ: 7.41-7.34 (m, 4H),7.33-7.28 (m, 2H), 7.18 (d, J=8.2 Hz, 2H), 3.16 (ddd, J=22.1, 12.5, 6.1Hz, 1H), 2.99 (dt, J=12.6, 6.7 Hz, 1H), 2.49 (s, 1H), 2.33-2.19 (m, 2H),2.19-2.09 (m, 1H), 1.90 (qdd, J=12.5, 5.1, 2.6 Hz, 1H), 1.68 (qdd,J=12.6, 5.1, 2.6 Hz, 1H), 1.29 (s, 9H), 1.27 (s, 9H), 1.05 (s, 1H),1.01-0.81 (m, 4H), 0.68 (t, J=7.0 Hz, 3H). ¹³C NMR (101 MHz, C₆D₆) δ:148.48, 148.46, 148.26, 141.54, 141.35, 137.32, 125.70, 125.39, 55.64,55.50, 50.08, 49.85, 47.97, 47.75, 35.53, 35.46, 34.59, 34.56, 34.44,34.42, 32.03, 32.01, 31.64, 31.61, 20.08, 14.07. ³¹P NMR (162 MHz, C₆D₆)δ: 71.44.

Step 7. Preparation ofrac-(2S,5S)—N-(bis(2-fluorophenyl)phosphanyl)-N-butyl-2,5-bis(4-tert-butylphenyl)phospholan-1-amine,L648

A cold (−35° C.) solution ofrac-(2S,5S)—N-butyl-2,5-bis(4-tert-butylphenyl)phospholan-1-amine (6)(0.25 g, 0.59 mmol) and triethylamine (0.09 mL, 0.65 mmol) in pentane(20 mL) was combined with a cold (−35° C.) solution ofbis(2-fluorophenyl)iodophosphine (0.21 g, 0.59 mmol) in pentane (20 mL),resulting in the rapid formation of a solid. After 2 h the reactionmixture was filtered through Celite and concentrated. After thevolatiles were removed, the residue was extracted with diethyl ether andfiltered through neutral alumina. The volatiles were removed undervacuum to yield the product (0.28 g, 74%). ¹H NMR (400 MHz, C₆D₆) δ:7.44 (dd, J=8.3, 1.7 Hz, 2H), 7.37 (t, J=8.8 Hz, 4H), 7.14-7.05 (m, 3H),6.90-6.80 (m, 3H), 6.77 (dddd, J=9.6, 8.3, 4.2, 1.2 Hz, 1H), 6.73-6.61(m, 3H), 4.42 (ddt, J=12.2, 8.4, 4.5 Hz, 1H), 3.33 (ddd, J=23.6, 13.5,5.3 Hz, 1H), 3.23-2.97 (m, 3H), 2.74-2.53 (m, 1H), 2.19 (tt, J=10.6, 5.3Hz, 1H), 1.68 (qd, J=12.5, 4.9 Hz, 1H), 1.27 (d, J=4.5 Hz, 18H), 0.98(d, J=8.0 Hz, 0H), 0.71-0.53 (m, 3H), 0.40 (t, J=7.0 Hz, 3H), ¹³C NMR(101 MHz, C₆D₆) δ: 165.66, 164.48, 164.32, 163.40, 162.05, 148.56,148.53, 148.11, 142.01, 141.81, 136.13, 136.11, 134.19, 134.12, 133.55,133.50, 131.55, 131.47, 130.41, 130.33, 128.75, 128.72, 128.70, 128.58,128.49, 128.18, 127.94, 125.72, 125.35, 124.30, 124.26, 124.21, 115.70,115.47, 115.11, 114.88, 55.48, 55.19, 54.86, 52.65, 52.46, 52.42, 37.25,34.47, 34.38, 34.33, 34.26, 33.39, 33.35, 33.30, 31.68, 31.61, 20.05,13.82. ³¹P NMR (162 MHz, C₆D₆) δ: 101.00, 32.49-30.79 (m). ¹⁹F NMR (376MHz, C₆D₆) δ: −102.79 (d, J=42.1 Hz), −104.27 (d, J=53.0 Hz).

Preparation ofrac-N-cyclobutyl-N-(bis(2,4-difluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L651 Step 1. Preparation ofrac-N-cyclobutyl-N-(bis(2,4-difluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L651

A cold solution (−30° C.) of triethylamine (0.079 g, 0.78 mmol) intoluene (1.6 mL) was added to a cold (−30° C.) solution ofrac-N-cyclobutyl-2,5-diphenylphospholan-1-amine (0.20 g, 0.64 mmol) intoluene (2.0 mL) and the resulting mixture was stirred for 10 min. Themixture was placed in a freezer at −30° C. for 30 minutes. To thiscooled reaction mixture was added a cold (−30° C.) solution ofbis(2,4-difluorophenyl)iodophosphine (0.22 g, 0.57 mmol) in 2.2 mL oftoluene with formation of a white precipitate. The reaction mixture wasstirred for 30 min at ambient temperature. The reaction mixture waspassed through a 5-cm plug of activated neutral alumina and the solventwas evaporated under vacuum giving solid product which wasrecrystallized from cold pentane at −30° C. to produce pure product.Yield 0.24 g (66.2%). ¹H NMR (400 MHz, C₆D₆, 70° C.) δ 7.27 (d, J=8.1Hz, 2H), 7.17 (d, J=7.5 Hz, 2H), 7.12-7.01 (m, 3H), 6.96-6.75 (m, 4H),6.45-6.25 (m, 5H), 4.14 (s, 1H), 3.59 (p, J=8.9 Hz, 1H), 3.19 (m, 1H),2.75 (d, J=15.2 Hz, 1H), 2.61 (m, 1H), 2.43 (m, 1H), 2.09-1.91 (m, 2H),1.72-1.31 (m, 4H), 1.11 (q, J=9.5 Hz, 1H). ¹³C NMR (101 MHz, C₆D₆, 70°C.) δ 165.48 (d, J=12.1 Hz), 162.98 (d, J=12.7 Hz), 162.41 (d, J=11.8Hz), 143.85 (d, J=21.3 Hz), 138.59 (d, J=2.6 Hz), 134.74-133.69 (m),128.32, 128.27 (d, J=4.1 Hz), 128.02, 127.95, 125.75 (d, J=2.6 Hz),125.47 (d, J=1.9 Hz), 111.11 (t, J=18.6 Hz), 103.48 (d, J=23.2 Hz),57.71 (d, J=15.5 Hz), 52.96 (d, J=19.8 Hz), 50.80 (dd, J=23.1, 3.4 Hz),36.21 (d, J=2.5 Hz), 33.07 (dd, J=8.1, 2.7 Hz), 31.79 (dd, J=12.8, 4.1Hz), 14.39. ³¹P NMR (162 MHz, C₆D₆, 70° C.) δ 81.98, 29.68. ¹⁹F NMR (376MHz, C₆D₆70° C.) δ 1.84-0.86 (m), −6.90, −8.98.

Preparation ofrac-N-cyclopentyl-N-(bis(2,4-difluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L652 Step 1. Preparation ofrac-N-cyclopentyl-N-(bis(2,4-difluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L652

A cold solution (−30° C.) of triethylamine (0.075 g, 0.74 mmol) intoluene (1.5 mL) was added to a cold (−30° C.) solution ofrac-N-cyclopentyl-2,5-diphenylphospholan-1-amine (0.20 g, 0.62 mmol) intoluene (2.0 mL) and the resulting mixture was stirred for 10 min. Themixture was placed in a freezer at −30° C. for 30 minutes. To thiscooled mixture was added a cold (−30° C.) solution ofbis(2,4-difluorophenyl)iodophosphine (0.21 g, 0.54 mmol) in 2.1 mL oftoluene, with formation of a white precipitate. The reaction mixture wasstirred for 30 min at ambient temperature. The reaction mixture waspassed through a 5-cm plug of activated neutral alumina and thevolatiles were removed under vacuum giving solid product which wasrecrystallized from cold pentane at −30° C. to produce pure product.Yield 0.14 g (39.1%). ¹H NMR (400 MHz, C₆D₆, 70° C.) δ 7.28 (d, J=7.6Hz, 2H), 7.19-7.06 (m, 4H), 7.02 (t, J=7.2 Hz, 1H), 6.92 (u J=7.5 Hz,2H), 6.84 (dd, J=9.7, 5.4 Hz, 2H), 6.55 (s, 1H), 6.50-6.25 (m, 4H), 4.12(s, 1H), 3.39 (m, 1H), 3.23 (m, 1H), 2.80 (s, 1H), 2.56-2.33 (m, 1H),2.12-1.84 (m, 2H), 1.50 (m, 2H), 1.44-0.89 (m, 6H). ¹³C NMR (101 MHz,C₆D₆, 70° C.) δ 165.53 (d, J=12.9 Hz), 164.88, 163.03 (d, J=12.5 Hz),162.27, 143.87 (d, J=21.2 Hz), 138.61 (d, J=2.7 Hz), 134.68 (q, J=8.8,8.3 Hz), 134.05, 128.29 (d, J=3.0 Hz), 128.07 (d, J=9.4 Hz), 127.93,125.62 (dd, J=21.6, 2.4 Hz), 121.45 (d, J=18.7 Hz), 111.03 (d, J=19.9Hz), 103.21 (dd, J=51.9, 26.8 Hz), 63.76 (d, J=15.7 Hz), 53.62, 50.82(dd, J=22.9, 3.7 Hz), 36.67 (d, J=3.0 Hz), 35.05 (dd, J=7.3, 3.2 Hz),33.65 (dd, J=12.4, 3.9 Hz), 32.95, 24.06 (d, J=5.9 Hz). ³¹P NMR (162MHz, C₆D₆, 70° C.) δ 84.22, 30.88. ¹⁹F NMR (376 MHz, 0ζ° C.) δ −99.62(m), −107.76, −110.46.

Preparation of(rac)-N-butyl-N-(di(thiophen-2-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L653 Step 1. Preparation ofN,N-dimethyl-1,1-di(thiophen-2-yl)phosphanamine

A 50-mL jar equipped with a stir bar and charged with THF (20 mL) andmagnesium turnings (0.825 g, 33.9 mmol) was cooled in the freezer to−30° C., 2-Bromothiophene (5.00 g, 30.8 mmol) dissolved in THF (10 mL)was added slowly to the stirring solution, and the reaction mixture wasstirred overnight. Analysis (a small aliquot was removed and quenchedwith deuterated water) by GC/MS showed the reaction to form thethiophenyl Grignard reagent was complete and the jar was placed in thefreezer at −30° C. A 200-mL jar equipped with a stir bar and chargedwith dimethylphosphoramidous dichloride (2.20 g, 15.1 mmol) in THF (75mL) was cooled in the freezer at −30° C. for 1 h. The cold thiophenylGrignard reagent (5.60 g, 30.1 mmol) was added slowly to the colddimethylphosphoramidous dichloride solution. The reaction mixture wasallowed to warm to room temperature while stirring overnight. Thereaction was checked by ³¹P NMR spectroscopy and found to be complete.The reaction mixture was concentrated to dryness under vacuum and theresidue was slurried in toluene (100 mL). The toluene mixture was thenpassed through a filter which was washed with more toluene (25 mL). Thevolatiles were removed and the residue was taken up in diethyl ether andfiltered. The filtrate was concentrated down and the residue wasdissolved in toluene. One third of the solution was saved for adifferent reaction. Two-thirds of the solution was collected and thesolvent was removed under vacuum to yield the product, 1.2 g, overallyield 1.8 g (79%). ¹H NMR (400 MHz, C₆D₆) δ 7.21 (ddd, J=4.6, 3.5, 1.1Hz, 2H), 7.14 (dd, J=4.9, 1.1 Hz, 2H), 6.81 (ddd, J=4.8, 3.5, 1.3 Hz,2H), 2.56 (d, J=10.8 Hz, 6H), ¹³C NMR (101 MHz, C₆D₆) δ 141.39 (d,J=30.9 Hz), 134.13 (d, J=24.3 Hz), 130.91 (d, J=2.3 Hz), 127.97 (d,J=6.1 Hz), 41.35 (d, J=15.2 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 41.94.

Step 2. Preparation of iododi(thiophen-2-yl)phosphine

A 50-mL jar was equipped with a stir bar and charged withN,N-dimethyl-1,1-di(thiophen-2-yl)phosphanamine (1.20 g, 4.97 mmol) andtoluene (7 mL). HCl in ether (1.00 M, 5.00 mL, 4.97 mmol) was addedslowly to the stirring reaction mixture. The reaction mixture wasstirred at room temperature overnight. The following day the reactionmixture was checked by ³¹P NMR spectroscopy whereupon it was determinedsome starting material (10%) was still present. Additional HCl in ether(1 mL) was added to the reaction mixture and it was stirred overnight atroom temperature. When checked by ³¹P NMR spectroscopy the followingday, the reaction had gone to completion. The solution was concentratedunder vacuum to afford crude chlorodi(thiophen-2-yl)phosphine (Yield0.63 g, 54%). ³¹P NMR (162 MHz, toluene-d₈) δ 47.92 (t, J=3.1 Hz). Thecrude chlorodi(thiophen-2-yl)phosphine was dissolved in toluene (7 mL)and transferred to a 40-mL vial equipped with a stir bar. The mixturewas cooled to −30° C. in the freezer and cold (−30° C.)iodotrimethylsilane (813 μL, 5.71 mmol) was added to the stirringreaction mixture causing an instant color change from light yellow todark yellow. The reaction mixture stirred at room temperature forseveral days. Analysis by ³¹P NMR spectroscopy showed the reaction to becomplete. The reaction mixture was concentrated down to afford theproduct as an orange solid. Yield (0.78 g, 89%). ¹H NMR (400 MHz, C₆D₆)δ 7.26 (ddd, J=6.0, 3.6, 1.1 Hz, 2H), 7.05 (ddd, J=4.9, 1.2, 0.4 Hz,2H), 6.56 (ddd, J=4.9, 3.6, 1.7 Hz, 2H), ¹³C NMR (101 MHz, C₆D₆) δ136.41 (d, J=34.3 Hz), 134.45 (d, J=1.5 Hz), 128.39. ³¹P NMR (162 MHz,C₆D₆) δ 2.45.

Step 3. Preparation of(rac)-N-butyl-N-(di(thiophen-2-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L653

A cold (−30° C.) solution of iododi(thiophen-2-yl)phosphine (0.130 g,0.402 mmol) in toluene (5 mL) was added dropwise to a cold (−30° C.)solution of (rac)-N-butyl-2,5-diphenylphospholan-1-amine (0.125 g, 0.402mmol) and triethylamine (62 μL, 0.40 mmol) in toluene (5 mL) causingimmediate solid formation. After stirring for 1 hour, the reactionmixture was analyzed by ³¹P NMR spectroscopy which showed completeconversion to the product. The toluene was removed under vacuum and theresidue was extracted with ether. The mixture was filtered through aplug of neutral activated alumina. The ether was removed under vacuum toyield a white solid. The solid was triturated with pentane and dried,affording the product as a white solid. Yield (0.133 g, 65.1%). ¹H NMR(400 MHz, C₆D₆) δ 7.41 (m, 2H), 7.31-7.19 (m, 5H), 7.16-6.99 (m, 6H),6.77 (ddd, J=4.8, 3.5, 1.2 Hz, 1H), 6.74-6.70 (m, 2H), 4.22 (m, 1H),3.38-3.12 (m, 3H), 3.09-2.96 (m, 1H), 2.51-2.38 (m, 1H), 2.25-2.12 (m,1H), 1.68-1.53 (m, 1H), 1.29-1.16 (m, 1H), 0.93-0.75 (m, 3H), 0.60-0.54(m, 3H). ¹³C NMR (101 MHz, C₆D₆) δ 144.63 (d, J=21.0 Hz), 143.59 (d,J=35.6 Hz), 140.51 (dd, J=32.1, 1.4 Hz), 139.43 (d, J=2.2 Hz), 135.42(d, J=27.9 Hz), 133.82 (d, J=23.2 Hz), 131.07 (dd, J=30.1, 1.9 Hz),129.10 (dd, J=3.4, 2.2 Hz), 128.87-128.46 (m), 127.51 (d, J=7.3 Hz),125.97 (dd, J=35.2, 2.2 Hz), 55.23-55.10 (m), 54.96-54.69 (m), 52.02(dd, J=22.9, 3.4 Hz), 36.33 (d, J=2.4 Hz), 34.10 (d, J=8.3 Hz), 33.38(dd, J=8.1, 3.3 Hz), 20.18, 13.92. ³¹P NMR (162 MHz, C₆D₆) δ 97.24 (d,J=27.6 Hz), 33.93 (d, J=27.6 Hz). HRMS (ESI-TOF) m/z: [M+H]+ Calcd forC₂₈H₃₁NP₂S₂ 508.1446; Found 508.1438.

Preparation of(rac)-N-(diphenylphosphanyl)-N,2,5-triphenylphospholan-1-amine, L654Step 1. Preparation of N,1,1-triphenylphosphanamine

A solution of chlorodiphenylphosphine (1.0 mL, 5.4 mmol) in hexanes (5.0mL) was added to aniline (1.1 mL, 12 mmol), causing a white precipitateto form. After stirring for 1 h, the mixture was filtered to remove thesalts and the filtrate was concentrated to yield the product as a whitesolid. Yield (1.3 g, 86%). ¹H NMR (400 MHz, C₆D₆) δ 7.44-7.33 (m, 4H),7.13-7.02 (m, 8H), 6.97-6.87 (m, 2H), 6.81-6.69 (m, 1H), 4.09 (d, J=7.6Hz, 1H), 33C NMR (101 MHz, C₆D₆) δ 147.04 (d, J=17.1 Hz), 140.72 (d,J=13.0 Hz), 131.59 (d, J=20.6 Hz), 129.56 (d, J=1.3 Hz), 129.18, 128.83,128.77, 119.87 (d, J=1.2 Hz), 116.52 (d, J=13.0 Hz). ³¹P NMR (162 MHz,C₆D₆) δ 28.93.

Step 2. Preparation of(rac)-N-(diphenylphosphanyl)-N,2,5-triphenylphospholan-1-amine, L654

A cold (−30° C.) solution of N,1,1-triphenylphosphanamine (0.25 g, 0.90mmol) and triethylamine (151 μL, 1.08 mmol) in toluene (2 mL) wascombined with a cold (−30° C.) solution of(rac)-2,5-diphenyliodophospholane (0.33 g, 0.90 mmol) in toluene (2 mL)and placed back in the freezer for 30 minutes. The solvent was thenremoved under vacuum and the residue was extracted with ether and passedthrough a plug of activated neutral alumina. After removing thevolatiles, the product was dissolved in pentane and crashed out in thefreezer to yield the product as a white solid. Yield 0.25 g, 54%. ¹H NMR(400 MHz, C₆D₆) δ 7.56-7.46 (m, 1H), 7.45-7.33 (m, 4H), 7.29-7.15 (m,6H), 7.15-6.85 (m, 10H), 6.71-6.62 (m, 2H), 6.42-6.32 (m, 2H), 4.08(ddt, J=10.9, 6.8, 3.4 Hz, 1H), 3.20 (ddd, J=25.1, 13.3, 5.8 Hz, 1H),2.35-2.09 (m, 2H), 2.08-1.91 (m, 1H), 1.57-1.30 (m, 1H). ¹³C NMR (101MHz, Benzene-d₆) δ 146.39 (t, J=4.6 Hz), 144.04 (d, J=22.0 Hz), 139.49,133.44 (d, J=20.8 Hz), 133.15 (d, J=22.0 Hz), 130.52 (d, J=2.8 Hz),128.83 (d, J=4.9 Hz), 128.65, 128.53 (d, J=3.8 Hz), 128.43, 128.34,127.65 (d, J=6.8 Hz), 125.97 (d, J=2.5 Hz), 125.43, 125.03, 52.97 (d,J=14.3 Hz), 52.81, 52.72 (d, J=9.8 Hz), 52.50 (d, J=6.1 Hz), 36.29 (d,J=2.1 Hz), 32.16 (d, J=4.1 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 100.50 (d,J=117.5 Hz), 68.64 (d, J=118.9 Hz).

Preparation ofrac-N-butyl-N-(bis(4-chloro-2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L664 Step 1. Preparation ofbis(4-chloro-2-fluorophenyl)diethylaminophosphine

n-Butyllithium in hexane (4.9 mL, 1.6 M, 7.8 mmol) was added slowly to acold (−78° C.) solution of 4-chloro-2-fluoro-1-iodobenzene (2.00 g, 7.80mmol) in ether (20.0 mL). The resulting reaction mixture was stirred forone hour at −78° C. A solution of diethylphosphoramidous dichloride(0.62 g, 3.6 mmol) in ether (1.0 mL) was added slowly at −78° C. Thereaction mixture was allowed to warm while stirring overnight. Thevolatiles were removed under reduced pressure. The solid was extractedwith hexanes, filtered, and the volatiles were removed under reducedpressure overnight to give a dark brown solid. Yield 1.14 g (89.1%). ¹HNMR (400 MHz, C₆D₆) δ 6.91 (m, 2H), 6.85-6.75 (m, 2H), 6.69 (m, 2H),2.78 (dq, J=9.8, 7.1 Hz, 4H), 0.71 (t, J=7.1 Hz, 6H), ¹³C NMR (101 MHz,C₆D₆) δ 164.42 (d, J=17.5 Hz), 161.95 (d, J=17.4 Hz), 135.86 (d, J=11.3Hz), 132.90 (t, J=6.9 Hz), 124.55 (d, J=3.7 Hz), 116.01 (d, J=27.1 Hz),44.67 (d, J=17.4 Hz), 14.04 (d, J=3.7 Hz). ³¹P NMR (162 MHz, C₆D₆) δ37.31 (t, J=44.0 Hz). ¹⁹F NMR (376 MHz, C₆D₆δ −102.23 (dt, J=44.0, 8.4Hz).

Step 2. Preparation of bis(4-chloro-2-fluorophenyl)chlorophosphine

A solution of HCl in ether (7.87 mL, 1.0 M, 7.87 mmol) was added to acold (−30° C.) solution ofbis(4-chloro-2-fluorophenyl)diethylaminophosphine (1.14 g, 3.15 mmol) indiethyl ether (10.0 mL). The reaction mixture was allowed to stir for 1h while warming to ambient temperature. The reaction mixture wasfiltered and the volatiles were removed under reduced pressure. Theresidue was extracted with hexanes and filtered. The volatiles wereremoved under reduced pressure to give the product as a dark brownsolid. ³¹P NMR spectra showed 59.9% of the desired product. Yield 0.47 g(46.1%). The product was used in the next step without furtherpurification. ¹H NMR (400 MHz, C₆D₆) δ 7.14 (m, 2H), 6.71 (m, 2H), 6.56(m, 1H), ¹³C NMR (101 MHz, C₆D₆) δ 164.34 (d, J=18.7 Hz), 161.84 (d,J=18.7 Hz), 138.36 (d, J=11.0 Hz), 133.34 (ddd, J=13.0, 3.9, 1.6 Hz),125.47-124.30 (m), 116.27 (d, J=26.3 Hz). ³¹P NMR (162 MHz, C₆D₆) δ63.95-53.04 (m). ¹⁹F NMR (376 MHz, C₆D₆) 8-102.09-−103.21 (m).

Step 3. Preparation of bis(4-chloro-2-fluorophenyl)iodophosphine

Iodotrimethylsilane (0.48 g, 2.2 mmol) was added to a solution ofbis(4-chloro-2-fluorophenyl)chlorophosphine (0.47 g, 1.4 mmol) intoluene (5.0 mL) to form an orange solution. The mixture was stirred atroom temperature overnight. The reaction mixture was filtered to removethe dark precipitate which was suspended in the solution after thereaction. The volatiles were evaporated under reduced pressure to give ayellowish liquid. ³¹P NMR spectra showed 71.4% of the desired product.Yield (0.51 g, 85%). ¹H NMR (400 MHz, C₆D₆) δ 7.15-7.03 (m, 2H), 6.63(ddt, J=8.3, 2.0, 0.6 Hz, 2H), 6.51 (ddd, J=9.3, 3.7, 2.0 Hz, 2H). ¹³CNMR (101 MHz, C₆D₆) δ 164.11 (d, J=18.4 Hz), 161.61 (d, J=18.5 Hz),138.46 (d, J=10.5 Hz), 136.78 (dd, J=11.6, 4.2 Hz), 125.15 (dd, J=3.8,1.9 Hz), 116.25 (d, 26.3 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 6.07 (t, J=57.2Hz). ¹⁹F NMR (376 MHz, C₆D₆δ −98.59 (dt, J=57.2, 8.5 Hz).

Step 4. Preparation ofrac-N-butyl-N-(bis(4-chloro-2-fluorophenyl)phosphinyl)-2,5-diphenylphospholan-1-amine,L664

A cold solution (−30° C.) of triethylamine (0.063 g, 0.63 mmol) intoluene-ds (1.3 mL) was added to a cold (−30° C.) solution ofrac-N-butyl-2,5-diphenylphospholan-1-amine (0.13 g, 0.42 mmol) intoluene-ds (1.3 mL) and the resulting mixture was stirred for 10 min.The mixture was placed in a freezer at −30° C. for 30 minutes. To thiscooled mixture was added a cold (−30° C.) solution ofbis(4-chloro-2-fluorophenyl)iodophosphine (0.17 g, 0.42 mmol) in toluene(1.7 mL), with formation of a white precipitate. The reaction mixturewas stilted for 30 min at ambient temperature. The reaction mixture waspassed through a 5-cm plug of activated neutral alumina and the solventwas evaporated under vacuum giving solid product which wasrecrystallized from cold pentane at −30° C. to produce pure product.Yield 0.05 g (20%). ¹H NMR (400 MHz, C₆D₆) δ 7.31 (dt, J=8.0, 1.5 Hz,2H), 7.19 (ddd, J=7.8, 4.3, 2.9 Hz, 4H), 7.06 (td, J=7.3, 1.3 Hz, 1H),6.90 (dd, J=8.2, 6.6 Hz, 2H), 6.82 (t, J=7.3 Hz, 1H), 6.75-6.58 (m, 5H),6.37 (td, J=7.7, 4.4 Hz, 1H), 4.10 (m, 1H), 3.16 (m, 1H), 2.98-2.71 (m,3H), 2.54-2.34 (m, 1H), 2.00 (dq, J=11.1, 5.3 Hz, 1H), 1.48 (dd, J=12.7,5.0 Hz, 1H), 1.01 (m, 1H), 0.61 (h, J=7.5, 7.0 Hz, 3H), 0.36 (t, J=7.1Hz, 3H). ¹³C NMR (101 MHz, C₆D₆) δ 165.00 (d, J=19.4 Hz), 163.11 (d,J=17.3 Hz), 162.52 (d, J=19.3 Hz), 160.64 (d, 17.2 Hz), 143.80 (d,J=20.9 Hz), 138.38 (d, J=2.3 Hz), 136.75 (d, J=10.5 Hz), 135.56-134.57(m), 133.63 (d, J=6.1 Hz), 128.44, 128.41-128.31 (m), 128.27 (d, J=6.4Hz), 128.15, 128.07, 125.89 (d, J=2.5 Hz), 125.63 (d, J=1.9 Hz), 124.56(d, J=3.4 Hz), 124.41 (d, J=3.4 Hz), 116.10 (d, J=27.5 Hz), 115.39 (d,J=26.8 Hz), 54.59 (d, J=27.2 Hz), 51.79 (dd, J=22.5, 4.6 Hz), 36.65 (d,J=1.8 Hz), 33.84 (dd, J=6.7, 2.2 Hz), 32.53 (dd, J=7.6, 3.5 Hz), 22.31,19.54, 13.86, 13.26. ³¹P NMR (162 MHz, C₆D₆) δ 101.47, 32.98-28.58 (m).¹⁹F NMR (376 MHz, C₆D₅CD₃) δ −112.24-−112.40 (m), −112.71 (m).

Preparation of(2R,5R)—N-butyl-N-(di(thiophen-3-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L665 Step 1. Preparation ofN,N-dimethyl-1,1-di(thiophen-3-yl)phosphanamine

A 40-mL vial equipped with a stir bar and charged with THF (5 mL) and3-bromothiophene (1.109 g, 6.852 mmol) was placed in the freezer (−30°C.) for two hours. Once removed from the freezer, isopropylmagnesiumchloride-lithium chloride complex solution in THF (5.270 mL, 1.30 M,6.85 mmol) that had also been in the freezer was added slowly to thestirring solution. The reaction mixture was stirred for two hours atroom temperature and then placed back in the freezer. A new 40-mL vialwas charged with dimethylphosphoroamidous dichloride (0.500 g, 3.43mmol) in THF (10 mL) and placed in the freezer for 1 hour. Both reagentswere removed and the 3-bromothiophene and isopropylmagnesiumchloride-lithium chloride complex reaction mixture was slowly added tothe dimethylphosphoroamidous dichloride solution. The reaction mixturestirred at room temperature for two and a half hours. The reaction wasfollowed by ³¹P NMR spectroscopy and was determined to be complete. Hiereaction mixture was concentrated down, extracted with toluene, andfiltered through a plug of neutral alumina. The filtrate was used in thenext step as-is. ¹H NMR (400 MHz, C₆D₆) δ 7.14-7.11 (m, 2H), 6.97-6.95(m, 4H), 2.45 (d, J=10.3 Hz, 6H). ¹³C NMR (101 MHz, C₆D₆) δ 130.60 (d,S=17.9 Hz), 129.55 (d, J=21.7 Hz), 126.20 (d, J=5.7 Hz), 41.53 (d,J=14.8 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 44.62.

Step 2. Preparation of chlorodi(thiophen-3-yl)phosphine

A mixture of N,N-dimethyl-1,1-di(thiophen-3-yl)phosphanamine and toluenein a 40 mL-vial was stirred while HCl in diethyl ether (4.25 mL, 1.0 M,4.25 mmol) was added slowly. The reaction mixture was stirred at roomtemperature for three and a half hours. The reaction was checked by ³¹PNMR spectroscopy and was determined to be complete. The reaction mixturewas filtered and concentrated down to afford 0.5305 g, 67.31%. ¹H NMR(400 MHz, C₆D₆) δ 7.11 (dddd, J=4.6, 2.8, 1.2, 0.4 Hz, 2H), 6.95 (dddd,J=5.0, 2.2, 1.2, 0.4 Hz, 2H), 6.72 (dddd, J=5.0, 2.8, 1.1, 0.4 Hz, 2H),¹³C NMR (101 MHz, C₆D₆) δ 138.88 (d, 35.5 Hz), 131.99 (d, J=33.5 Hz),129.34 (d, J=16.0 Hz), 127.17 (d, J=5.1 Hz). ³¹P NMR (162 MHz, C₆D₆) δ57.83.

Step 3. Preparation of iododi(thiophen-3-yl)phosphine

A 40-mL vial was equipped with a stir bar and charged withchlorodi(thiophen-3-yl)phosphine (0.484 g, 2.0814 mmol) in toluene (7mL). The vial was placed in the freezer (about −30° C.) for fifteenminutes. Once removed from the freezer, iodotrimethylsilane (355 μL,2.50 mmol) that had also been in the freezer was added slowly to thestirring solution. The reaction mixture immediately changed from lightyellow to dark yellow. The reaction mixture was stirred for three and ahalf hours. The course of the reaction was checked by ³¹P NMRspectroscopy and was determined to be complete. The reaction mixture wasconcentrated down to afford 0.591 g, 87.6%. ¹H NMR (400 MHz, C₆D₆) δ7.14-7.07 (m, 4H), 6.77 (ddd, J=5.0, 2.8, 1.1 Hz, 2H), ¹³C NMR (101 MHz,C₆D₆) δ 132.50 (d, J=32.3 Hz), 131.89 (d, J=15.0 Hz), 127.52 (d, J=4.8Hz). ³¹P NMR (162 MHz, C₆D₆) δ 5.90.

Step 4. Preparation of(2R,5R)—N-butyl-N-(di(thiophen-3-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L665

A cold (−30° C.) solution of iododi(thiophen-3-yl)phosphine (0.260 g,0.836 mmol) in toluene (5 mL) was added dropwise to a cold (−30°Qsolution of (rac)-N-butyl-2,5-diphenylphospholan-1-amine (0.200 g, 0.643mmol) and triethylamine (99 μL, 0.707 mmol) toluene (5 mL) causingimmediate solid formation. After stirring for 1 hour, the sample wasanalyzed by ³¹P NMR spectroscopy which showed complete conversion to theproduct. The toluene was removed under vacuum, the residue was extractedwith ether, and filtered through a plug of neutral activated alumina.The ether was removed under vacuum to yield a white solid. The solid wastriturated with cold pentane and dried, affording 0.220 g, 67.53% as awhite solid. ¹H NMR (400 MHz, C₆D₆) δ 7.46-7.40 (m, 2H), 7.30-7.13 (m,7H), 7.12-7.06 (m, 3H), 6.90-6.88 (m, 2H), 6.77 (ddd, J=4.9, 2.8, 1.3Hz, 1H), 6.58 (td, J=2.9, 1.2 Hz, 1H), 6.38 (ddd, J=4.9, 2.0, 1.2 Hz,1H), 4.04 (ddt, J=12.3, 7.4, 4.7 Hz, 1H), 3.39-3.25 (m, 1H), 3.08-2.85(m, 3H), 2.44-2.31 (m, 1H), 2.21-2.11 (m, 1H), 1.10-0.98 (m, 1H),0.78-0.61 (m, 3H), 0.53-0.47 (m, 3H), ¹³C NMR (101 MHz, C₆D₆) δ 144.65(d, J=20.9 Hz), 141.81 (d, J=25.3 Hz), 139.78 (d, J=2.3 Hz), 139.17 (d,J=18.4 Hz), 131.37-130.22 (m), 129.52 (d, J=19.2 Hz), 129.31-129.14 (m),128.89-128.52 (m), 126.50 (d, J=5.7 Hz), 126.23 (d, J=2.5 Hz), 125.85(d, J=1.9 Hz), 125.33 (d, J=5.9 Hz), 55.85-55.31 (m), 54.63 (dd, J=31.5,5.9 Hz), 51.87 (dd, J=22.5, 3.4 Hz), 36.77 (d, J=2.7 Hz), 34.14 (d,J=7.2 Hz), 33.26 (dd, J=7.9, 3.4 Hz), 20.10, 13.89. ³¹P NMR (162 MHz,C₆D₆) δ 97.06 (d, J=24.4 Hz), 37.46 (d, J=24.4 Hz).

Preparation of(2R,5R)—N-butyl-N-(di(furan-3-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L696 Step 1. Preparation of N,N-dimethyl-1,1-di(furan-3-yl)phosphanamine

n-Butyllithium (6.86 mL, 2.5 M, 17 mmol) was slowly added to a chilled(−70° C. (dry-ice acetone bath)) solution of 3-bromofuran (2.832 g,19.270 mmol) in THF (˜40 mL) in a 250-mL three-necked round bottom flaskequipped with a stir bar and a thermocouple. The reaction mixture wasstirred at −70° C. for 2 hours. A solution of dimethylphosphoramidousdichloride (1.250 g, 8.565 mmol) in THF (˜40 mL) was then slowly addedby syringe. The reaction mixture was stirred for 2 hours. Analysis ofthe crude reaction mixture by ³¹P NMR spectroscopy showed the reactionwas complete. The bright yellow reaction mixture was carried on to thenext step as is. ³¹P NMR (162 MHz, THF) δ 20.41 (s).

Step 2. Preparation of chlorodi(furan-3-yl)phosphine

To the reaction mixture (comprisingN,N-dimethyl-1,1-di(furan-3-yl)phosphanamine in THF) from the previousstep, still at −70° C., was added a solution of HCl in diethyl ether(18.85 mL, 1.0 M, 19 mmol). The reaction mixture was stirred overnightwhile warming up to room temperature. Analysis of the crude reactionmixture by ³¹P NMR spectroscopy showed the reaction was complete. Thereaction mixture was taken back into a glovebox and the crude mixturewas filtered through Celite and concentrated down to afford 0.922 g,53.68% of light yellow solid. ¹H NMR (400 MHz, C₆D₆) δ 7.24-7.22 (m,1H), 7.14 (dd, J=1.5, 0.9 Hz, 1H), 7.04-7.00 (m, 1H), 6.94 (td, J=1.7,0.9 Hz, 1H), 6.35-6.33 (m, 1H), 6.31 (td, J=1.8, 0.9 Hz, 1H), ¹³C NMR(101 MHz, C₆D₆) δ 147.79 (d, J=20.2 Hz), 147.46 (d, J=4.5 Hz), 144.71(d, J=5.0 Hz), 143.91 (t, J=2.5 Hz), 113.55 (t, J=6.1 Hz), 111.82 (d,J=8.2 Hz). ³¹P NMR (162 MHz, C₆D₆) δ 40.26.

Step 3. Preparation of di(furan-3-yl)iodophosphane

A 40-mL vial equipped with a stir bar and containing a solution ofchlorodi(furan-3-yl)phosphane (0.500 g, 85% pure by ³¹P NMR, 2.493 mmol)in toluene (7 mL) was placed in the freezer (−30° C.) for 45 minutes.Cold iodotrimethylsilane (362 μL, 2.543 mmol) that had been in thefreezer was added to the stirring reaction mixture. The reaction mixturewas allowed to warm to ambient temperature. Analysis after 15 minutes by³¹P NMR spectroscopy showed the reaction was complete. The reactionmixture was concentrated down to afford 0.3059 g, 49.43% of dark yellowoil. ¹H NMR (400 MHz, C₆D₆) δ 7.26-7.20 (m, 1H), 7.12-7.08 (m, 1H),7.05-7.00 (m, 1H), 6.99-6.94 (m, 1H), 6.35-6.30 (m, 2H), ¹³C NMR (101MHz, C₆D₆) δ 147.34, 146.92, 144.60 (d, J=5.1 Hz), 143.90 (t, J=2.4 Hz),114.13 (d, J=8.1 Hz), 113.55 (t, J=6.1 Hz). ³¹P NMR (162 MHz, C₆D₆) δ−14.79.

Preparation of(2R,5R)—N-butyl-N-(di(furan-3-yl)phosphanyl)-2,5-diphenylphospholan-1-amine,L696

A cold (30 minutes in a −30° C. freezer) solution ofdi(furan-3-yl)iodophosphane (0.255 g, 60% pure by ³¹P NMR, 0.857 mmol)in toluene (5 mL) was added dropwise to a cold (30 minutes in a −30° C.freezer) solution of (rac)-N-butyl-2,5-diphenylphospholan-1-amine (0.160g, 0.514 mmol) and triethylamine (79 μL, 0.565 mmol) in toluene (5 mL),causing immediate formation of precipitate. The reaction mixture wasstirred for 45 minutes. Analysis by ³¹P-NMR spectroscopy showed thereaction had reached complete conversion. The toluene was removed undervacuum, the residue was extracted with ether and filtered through a plugof neutral activated alumina. The ether was removed under vacuum toyield an oil which was analyzed by ³¹P-NMR and found to contain someimpurities. The product was purified by passing a toluene solution ofthe oil through a plug of basic alumina. The filtrate was concentrateddown to afford the product as a light yellow oil, 41.3 mg, 16.9%. ¹H NMR(500 MHz, C₆D₆) δ 7.40-7.35 (m, 2H), 7.27-7.21 (m, 3H), 7.20-7.16 (m,2H), 7.14-7.11 (m, 2H), 7.06-7.00 (m, 3H), 6.96 (q, J=1.5 Hz, 1H), 6.69(dt, J=1.4, 0.7 Hz, 1H), 6.15 (dt, J=1.9, 1.0 Hz, 1H), 5.70 (dt, 1.9,1.0 Hz, 1H), 4.00 (ddt, J=12.3, 7.4, 4.7 Hz, 1H), 3.34-3.21 (m, 1H),3.00-2.79 (m, 3H), 2.41-2.29 (m, 1H), 2.12 (ddt, J=14.8, 13.0, 5.2 Hz,1H), 1.61-1.48 (m, 1H), 1.26-1.13 (m, 1H), 0.88-0.65 (m, 3H), 0.56-0.52(m, 3H), ¹³C NMR (126 MHz, C₆D₆) δ 147.01 (d, J=29.6 Hz), 146.24 (d,J=29.5 Hz), 143.84 (d, J=5.3 Hz), 143.07 (d, J=5.7 Hz), 139.85 (d, J=2.4Hz), 129.23-129.08 (m), 128.91-128.46 (m), 126.23 (d, J=2.4 Hz), 125.84(d, J=1.6 Hz), 112.99 (d, J=12.7 Hz), 112.59 (d, J=12.8 Hz), 55.14 (t,J=21.3 Hz), 54.19 (dd, J=30.4, 5.7 Hz), 51.49 (dd, J=22.4, 3.8 Hz),36.32 (d, J=2.9 Hz), 34.22 (d, J=7.7 Hz), 33.17 (dd, J=7.8, 3.4 Hz),20.15, 13.93. ³¹P NMR (202 MHz, C₆D₆) δ 96.13 (d, J=22.8 Hz), 15.59 (d,J=22.9 Hz).

Preparation of a mixture of4,8-di-tert-butyl-N-butyl-N-((2S,5S)-2,5-diphenylphospholan-1-yl)-S-1,2,10,11-tetramethyldibenzo[d,f][1,3,2]dioxaphosphepin-6-amineand4,8-di-tert-butyl-N-butyl-N-((2R,5R)-2,5-diphenylphospholan-1-yl)-S-1,2,10,11-tetramethyldibenzo[d,f][1,3,2]-dioxaphosphepin-6-amine,L699

A cold solution (−30° C.) of triethylamine (0.117 g, 1.16 mmol) intoluene (1.2 mL) was added to a cold (−30° C.) solution ofrac-N-butyl-2,5-diphenylphospholan-1-amine (0.30 g, 0.96 mmol) intoluene (3.0 mL) and the resulting reaction mixture was stirred for 10min. The reaction mixture was placed in a freezer at −30° C. for 30minutes. To this cooled reaction mixture, was added a cold (−30° C.)solution ofS-4,8-di-tert-butyl-6-iodo-1,2,10,11-tetramethyldibenzo[d,f][1,3,2]dioxaphosphepine (0.49 g, 0.96 mmol) in 4.9 mL of toluene. After theaddition of the solution was complete, a white precipitate was observed.The solution was stirred for 30 min at ambient temperature. Thevolatiles were removed under vacuum. The crude product was extractedwith toluene (10 mL) and filtered through 5 cm of activated neutralalumina. The volatiles were removed from the filtrate under vacuumgiving solid product which was recrystallized from cold pentane at −30°C. to yield a mixture of two isomeric products. Yield 0.38 g (69.9%). XUNMR (400 MHz, C₆D₆) δ 7.46 (m, 4H), 7.39-7.32 (m, 2H), 7.29 (m, 2H),7.25-7.13 (m, 8H), 7.10-6.89 (m, 8H), 4.77 (m, 1H), 3.90 (m, 1H), 3.30(m, 1H), 3.09-2.33 (m, 9H), 2.31-2.09 (m, 2H), 2.09-1.91 (m, 12H), 0.71(s, 3H), 1.70 (s, 3H), 1.69 (s, 9H), 1.68 (s, 9H), 1.65-1.47 (m, 8H),1.43 (s, 9H), 1.34-1.23 (m, 1H), 1.09 (s, 9H), 0.89-0.46 (m, 9H), 0.35(m, 6H), 0.26-0.10 (m, 1H), ¹³C NMR (101 MHz, C₆D₆) δ 148.53, 148.43,148.30, 148.24, 147.87, 147.58, 146.07, 145.82, 144.66, 144.45, 138.79,137.73 (d, J=2.4 Hz), 137.67-137.34 (m), 137.22, 136.66, 134.87 (d,J=8.3 Hz), 134.08, 133.72, 132.30 (d, J=5.0 Hz), 131.99, 131.81, 130.44,130.34 (d, J=3.0 Hz), 130.20, 129.96, 128.90, 128.87-128.76 (m), 128.64,128.57 (d, J=3.7 Hz), 128.39, 128.34 (d, J=2.3 Hz), 128.29, 128.20 (t,J=2.3 Hz), 128.13, 126.06 (d, J=1.9 Hz), 125.98-125.69 (m), 125.26,59.15 (d, J=27.2 Hz), 54.83 (d, J=27.5 Hz), 54.07-53.06 (m), 52.11-50.21(m), 37.95, 37.40, 35.94 (d, J=12.2 Hz), 35.35 (d, J=7.7 Hz),35.23-34.37 (m), 33.90, 33.15 (d, J=3.6 Hz), 31.69-30.74 (m), 30.36,21.01, 20.58-19.33 (m), 16.56-14.90 (m), 12.70 (d, J=26.3 Hz). ³¹P NMR(162 MHz, C₆D₆ δ 143.44-143.17 (m), 102.02 (d, J=27.6 Hz), 92.14 (d,J=13.5 Hz).

Ligating Compound-Chromium Complex Preparation Preparation of1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene-CrCl₃((tetrahydrofuran)),(Me-DuPhos-CrCl₃(THF)), L372

THF (15 mL) was added to a vial containing1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene, (Me-DuPhos), (0.60 g,1.96 mmol) and trichlorotris(tetrahydrofuran)chromium (CrCl₃(THF)₃),0.56 g, 1.51 mmol). The resulting solution was stirred for 30 min atambient temperature and then heated for 1 h at 60° C. The THF wasconcentrated with formation of more crystalline material. Thesupernatant was pipetted away from the solids. The solids were driedunder reduced pressure to give violet-black crystalline material, 0.4776g, 59.0%. Crystals suitable for X-ray diffraction analysis were grown byslow evaporation of a THF solution at ambient temperature. ElementalAnalysis: Calculated: C, 49.22; H, 6.76; Found: C, 49.24; H, 6.69.Crystal structure is given in FIG. 1.

Preparation of (1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene-CrCl₃)₂((Me-DuPhos-CrCl₃)₂), L423

Toluene (8 mL) was added to a vial containing1,2-bis[(2S,5S)-2,5-dimethylphospholano]benzene (0.588 g, 1.92 mmol) andCrCl₃(THF)₃ (0.7133 g, 1.92 mmol). The reaction mixture was heatedovernight at 80° C., giving a suspension. The suspension was filteredwithout cooling to yield an amorphous solid product. The product waswashed with 2 mL of toluene and 8 mL of hexanes, and was then driedunder reduced pressure giving 0.7655 g (yield=85.8%) of crystallinematerial. Elemental Analysis: Calculated: C, 46.52; H, 6.07; Found: C,46.32; H, 5.97. Crystals suitable for X-ray diffraction analysis weregrown from a CD₂Cl₂/hexanes solution of the material at ambienttemperature. Crystal structure is given in FIG. 2.

Preparation of(1,2-bis[(2R,5R)-2,5-diethylphospholano]benzene-CrCl₃(THF)(Et-DuPhos-CrCl₃(THF), L403)

CrCl₃(THF)₃ (513 mg, 1.38 mmol) was dissolved in THF (5 mL) to give apurple solution. A solution of1,2-bis[(2R,5R)-2,5-diethylphospholano]benzene, (Et-DuPhos), (500 mg,0.60 mmol) in THF (5 mL) was added dropwise to the CrCl₃(THF)₃ solution.Almost immediately upon addition of the ligand, the solution colorchanged to a deep cobalt blue. The reaction mixture was stirred for 8hours and then the solvent was removed in vacuo. The resulting bluesolid was dried under vacuum at 60° C. overnight. Yield 506.7 mg, 62%.Crystals suitable for X-ray diffraction analysis were grown byevaporation of a THF/hexanes solution at ambient temperature. ElementalAnalysis: Calculated: C, 52.67; H, 7.48; N, 0.00. Found: C, 52.43; H,7.26. Crystal structure is given in FIG. 3.

Preparation of 1,2-bis[(2R,5R)-2,5-dimethylphospholano]ethane-CrCl₃(THF)(Me-BPE-CrCl₃(THF), L42P

CrCl₃(THF)₃ (360 mg, 0.97 mmol) was dissolved in THF (5 mL) to give apurple solution. A solution of1,2-bis[(2R,5R)-2,5-dimethylphospholano]ethane, (Me-BPE), (250 mg, 0.97mmol) in THF (5 mL) was added dropwise to the CrCl₃(THF)₃ solution. Thesolution color immediately changed from purple to a dark cobalt blue.The solution was allowed to stir overnight at ambient temperature. TheTHF was removed in vacuo and the residue was redissolved in a minimalamount of THF (˜5 mL), followed by addition of hexanes (˜30 mL). Thissuspension was filtered through a frit, and the solvent was removed fromthe filtrate in vacuo to yield 299.9 mg of a blue solid. Yield 63.4%.Crystals suitable for X-ray diffraction analysis were grown byevaporation of a THF/hexanes solution at ambient temperature. ElementalAnalysis: Calculated: C, 44.23; H, 7.42; N, 0.00. Found: C, 42.93; H,7.25. Crystal structure is given in FIG. 4.

Preparation of 1,2-bis[(2R,5R)-2,5-diethylphospholano]ethane-CrCl₃(THF),(Et-BPE-CrCl₃(THF), L422)

CrCl₃(THF)₃ (295 mg, 0.80 mmol) was dissolved in THF (5 mL) to give apurple solution. A solution of1,2-bis[(2R,5R)-2,5-diethylphospholano]ethane. (Et-BPE), (250 mg, 0.80mmol) in THF (5 mL) was added to the CrCl₃(THF)₃ solution. The reactionmixture was allowed to stir overnight at ambient temperature and then 30mL of hexanes were added. The resulting suspension was filtered througha frit. The solvent was removed from the filtrate in vacuo to yield 354mg of a blue solid. Yield 81.7%. Crystals suitable for X-ray diffractionanalysis were grown by evaporation of a THF/hexanes solution at ambienttemperature. Elemental Analysis: Calculated: C, 48.49; H, 8.14; N, 0.00.Found: C, 43.79; H, 7.84. Crystal structure is given in FIG. 5.

Preparation of(1R,1R,2S,2′S)-2,2′-di-tert-butyl-2,3,2′,3′-tetrahydro-1H,1′H-(1,1′)biisophosphindolyl-CrCl₃(THF),(DuanPhos-CrCl₃(THF), L455)

Cr(THF)₃Cl₃ (98.0 rag, 0.26 mmol) was dissolved in THF (3 mL) to give apurple solution. A solution of(1R,1′R,2S,2′S)-2,2′-di-tert-butyl-2,3,2′,3′-tetrahydro-1H,1′H-(1,1′)biisophosphindolyl,(DuanPhos) (100 mg, 0.26 mmol) in THF (5 mL) was added to theCr(THF)₃Cl₃ solution. The solution color changed from purple to bluewithin minutes of the ligand addition. The reaction mixture was allowedto stir for four days at ambient temperature. Hexanes (30 mL) was addedto the reaction mixture, and the resulting suspension was filteredthrough a frit, yielding 108.2 mg of a blue solid. Yield 67.5%. Crystalsof suitable for X-ray diffraction analysis were grown from CD₂Cl₂ andhexanes at ambient temperature. The resulting crystal structure is ofthe dimer complex: (DuanPhos-CrCl₃)₂. Because elemental analysisindicated a monomelic structure, it is apparent that the complexdimerized under the crystallization conditions. Elemental Analysis:Calculated: C, 54.87; H, 6.58; Found: C, 55.48; H, 6.96.

Preparation of((rac)-N-(diphenylphosphanyl)-N-methyl-2,5-diphenylphospholan-1-amine)-CrCl₃(THF),L560

CrCl₃(THF)₃ (65.2 mg, 0.17 mmol) was dissolved in toluene (2 mL) to givea purple solution. A solution of((rac)-N-(diphenylphosphanyl)-N-methyl-2,5-diphenylphospholan-1-amine)(86.3 mg, 0.17 mmol) in toluene (8 mL) was added to the Cr(THF)₃Cl₃solution. The solution color changed to a dark purple-black. Thereaction mixture was allowed to stir overnight at ambient temperature.The reaction mixture was filtered and the solvent was removed in vacuo,yielding 54.5 mg of a blue solid. Yield 43.1%. Elemental Analysis:Calculated: C, 41.94; H, 5.63. Found: C, 41.89; H, 5.57. Purple,plate-like crystals suitable for X-ray diffraction were grown from amixture of dichloromethane and chloroform at −20° C. Because elementalanalysis confirmed the bulk composition to be the monomelic species, itis apparent that the dimer structure formed under the crystallizationconditions. Crystal structure is shown in FIG. 7.

Comparative Example (CEx) A—Preparation oftrichloro[N,N-bis(diphenylphosphino)-N-isopropylamine](tetrahydrofuran)chromium,L404a

A 20 mL vial was charged with solid N,N-bis(diphenylphosphino)-isopropylamine, (obtained as described inBollmann et at, (“Ethylene Tetramerization: A New Route to Produce1-Octene in Exceptionally High Selectivities”, Bollmann, A.; Blann, K.;Dixon, J. T.; Hess, F. M.; Killian, E.; Maumela. H.; McGutnness, D. S.;Morgan, D. H.; Neveling, A.; Otto, S.; Overett, M.; Slawin, A. M. Z.;Wasserscheid, P.; Kuhlmann, S. J. Am. Chem. Soc. 2004, 126,14712-14713)), (0.100 g, 0.234 mmol) and solidtrichlorotris(tetrahydrofuran)chromium, (2), (0.087 g, 0.213 mmol).Toluene (8 mL) was added to the vial and the vial contents were shaken.A deep blue-black color developed within 5 minutes in the solution whichcontained a significant amount of undissolved solids. The vial contentswere shaken well and allowed to stand overnight to yield a solution withvery little undissolved solids. The solution was filtered using asyringe filter into a 20-mL vial and the contents of the vial wereallowed to stand overnight during which time several very large crystalsformed. The crystals, once recovered from the vial and dried, wereanalyzed by single crystal XRD. Elemental analysis fortrichloro[N,N-bis(diphenylphosphino)-N-isopropylamine](tetrahydrofuran)chromiumas a mono toluene solvate: calculated: C, 60.85; H, 5.78; N, 1.87;found: C, 60.28; H, 5.69, N, 1.62. Crystal structure is shown in FIG. 6.

Comparative Example (CEx) B—Preparation oftrichloro[N,N-bis(1,3,2-dioxaphospholane)-N-isopropylamine](tetrahydrofuran)chromium,L430 Step 1. Preparation ofN,N-bis(1,3,2-dioxaphospholanyl)-N-isopropylamine, L429

Triethylamine (9.8 mL, 70.6 mmol) was added to a solution of2-chloro-1,3,2-dioxaphospholane (1.7 mL, 19.1 mmol) in dichloromethane.The reaction mixture was cooled to −28° C. and allowed to sit at thattemperature for one hour. Isopropyl amine (0.7 mL, 8.6 mmol) was addedand the reaction mixture was allowed to warm to ambient temperature andstir overnight. A white precipitate was observed. The reaction mixturewas filtered and the filtrate was concentrated in vacuo. The residue wasdissolved in a small amount of hexanes. The product precipitated fromthe hexanes as 0.86 g of a white solid. Yield 42%. ¹H NMR (400 MHz,CDCl₃) δ 4.16-4.04 (m, 4H), 3.92-3.78 (m, 4H), 3.50-3.33 (m, 1H), 1.27(s, 3H), 1.25 (s, 3H), ¹³C NMR (101 MHz, CDCl₃) δ 64.30 (m), 45.88 (s),44.97 (t), 25.58 (t). ³¹P NMR (162 MHz, CDCl₃) δ 143.50.

Step 2. Preparation oftrichloro[N,N-bis(1,3,2-dioxaphospholane)-N-isopropylamine]-(tetrahydrofuran)chromium,L430

A solution of N,N-bis(1,3,2-dioxaphospholanyl)-N-isopropylamine (100 mg,0.42 mmol) in toluene (5 mL) was added to a purple mixture ofCrCl₃(THF)₃ (156.7 mg, 0.42 mmol) in toluene (5 mL) giving a bluesolution. The reaction mixture was allowed to stir overnight at ambienttemperature. The reaction mixture was filtered, yielding 97.5 mg of ablue solid. Yield 49.7%. Elemental Analysis: Calculated: C, 28.2; II,4.73; N, 2.99. Found: C, 29.15; H, 5.18; N, 3.20.

Comparative Example (CEx) C—Preparation oftrichloro[N,N-bis(5,5-dimethyl-1,3,2-dioxaphosphorinanyl)-N-isopropylamine](tetrahydrofurantchromium,L431 Step 1. Preparation ofN,N-bis(5,5-dimethyl-1,3,2-dioxaphosphorinanyl)-N-isopropylamine, L417

Triethylamine (9.6 mL, 69.3 mmol) was added to a solution of2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane (2.6 mL, 18.7 mmol) indichloromethane. The reaction mixture was cooled to −28° C. and allowedto sit at that temperature for one hour. Isopropyl amine (0.7 mL, 8.6mmol) was added and the reaction mixture was allowed to warm to ambienttemperature and stir overnight. A white precipitate was observed. Thereaction mixture was filtered and the filtrate was concentrated invacuo. The residue was dissolved in a small amount of hexanes. Theproduct precipitated from the hexanes and was filtered out to yield 1.2g (44% yield) of a white solid. NMR (400 MHz, CD₂Cl₂) δ 4.39-4.23 (m,1H), 3.85-3.66 (m, 8H), 1.35 (s, 3H), 1.33 (s, 3H), 1.15 (s, 6H), 0.81(s, 6H), ¹³C NMR (101 MHz, CD₂Cl₂) δ 74.87 (t), 45.69 (t), 33.26 (t),26.17 (t), 23.35 (t), 22.07 (s). ³¹P NMR (162 MHz, CD₂Cl₂) δ 143.12.

Step 2. Preparation oftrichloro[N,N-bis(5,5-dimethyl-1,3,2-dioxaphosphorinanyl)-N-isopropylamine]-(tetrahydrofuran)chromium,L431

A solution ofN,N-bis(5,5-dimethyl-1,3,2-dioxaphosphorinanyl)-N-isopropylamine (100mg, 0.31 mmol) in toluene (5 mL) was added to a purple mixture ofCrCl₃(THF)₃ (115.9 mg, 0.31 mmol) in toluene (5 mL) giving a bluesolution. The reaction mixture was allowed to stir overnight at ambienttemperature. The reaction mixture was filtered, yielding 57.3 mg of ablue solid. Yield 33.5%. Crystals suitable for X-ray diffractionanalysis were grown by evaporation of a THF/hexanes solution of theproduct at ambient temperature.

Comparative Example (CEx) D—Preparation oftrichloro[1,2-bis(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)benzene](tetrahydrofuran)chromium,L453 Step 1. Preparation of1,2-bis(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)benzene

A solution of triethylamine (1.79 mL, 12.86 mmol) and1,2-bis(dichlorophosphanyl)benzene (0.8 mL, 2.86 mmol) indichloromethane (30 mL) was cooled to −35° C. for one hour.2,2-Dimethylpropane-1,3-diol (0.56 g, 5.72 mmol) was slowly added to thecold solution over 15 minutes, causing the formation of a whiteprecipitate. The resulting slurry was allowed to stir for ˜24 h beforebeing filtered. The filtrate v/as concentrated in vacuo giving anoff-white solid. Recrystallization from hot hexanes afforded 0.6 g ofthe product as a white solid. Yield 61%. NMR (500 MHz, CDCl₃) δ7.60-7.56 (br m, 2H), 7.45 (t, 2H), 3.68-3.43 (m, 9H), 1.29 (s, 6H),0.55 (s, 6H), ¹³C NMR (101 MHz, CDCl₃) δ 143.32 (d, J_(C-P)=14.51 Hz),142.79 (d, J_(C-P)=14.68 Hz), 130.97, 130.85, 129.23, 129.21, 72.02,72.00, 71.98, 71.96, 33.17, 33.13, 22.63, 22.58. ³¹P NMR (202 MHz,CDCl₃) δ 147.53.

Step 2. Preparation oftrichloro[1,2-bis(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)benzene](tefrahydrofuran)chromium, L453

A solution of 1,2-bis(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)benzene(150 mg, 0.44 mmol) in toluene (5 mL) was added to a purple mixture ofCrCl₃(THF)₃ (164.2 mg, 0.44 mmol) in toluene (5 mL) to give a bluesolution. The reaction mixture was allowed to stir overnight at ambienttemperature. The reaction mixture was filtered and the solvent wasremoved in vacuo, yielding 164.8 mg of a blue solid. Yield 70.1%.Elemental Analysis: Calculated: C, 41.94; H, 5.63. Found: C, 41.89; H,5.57.

Ethylene Oligomerization Reactions

Solvents and gases used in the ethylene oligomerization reactions werepurified as follows: The nitrogen and ethylene gas feeds andmethylcyclohexane solvent were passed through purification columnscontaining activated A2 alumina and Q5 reactant. Chlorobenzene andnonane were passed through activated A-204 alumina. Themethylcyclohexane, chlorobenzene, and nonane were stored over activated3 Å molecular sieves. The A2 alumina, A204 alumina, and molecular sieveswere activated as described above. MMAO-3A was obtained from AkzoNobel.

High-Throughput Experimental Information

The hot-oil pressure reactor (HOPR), a high-throughput reactor housed ina nitrogen-filled glovebox in which reactions are performed in some orall of 24 individual cells in a stainless steel block fitted with 8-mLglass inserts, is used to perform a series of oligomerizationexperiments using certain of the catalyst systems prepared above. Thecells in the HOPR can be pressurized up to 500 pounds per square inch(psi) (3.45 megapascals (MPa)); however, all the cells share a commonheadspace and gas uptake profiles for individual reactions cannot bemonitored with this apparatus. Efficient mixing is achieved through theuse of magnetic stir bars.

Library Studio software from Freeslate was used to make designs forrunning the libraries of 24 experiments in the HOPR. In running thelibrary, each glass insert was equipped with a stir bar and then theglass insert and stir bar combination was weighed to use as a basis fordetermining the weight of residual solids after completing anexperimental run. The inserts were arranged in a 24-sample reactor plate(6×4) and a predetermined amount of methylcyclohexane solvent was addedvia a liquid handler such that the final volume after the addition ofall other components would be 4 mL. The liquid handler then delivered asolution of 10 wt % nonane, the GC internal standard, inmethylcyclohexane, for a total of 50 mg of nonane in each glass insert.The components of the catalyst system (comprising a solution of theselected activator and a solution of the selected precatalyst) were thenadded to the glass inserts via an Eppendorf pipette to form reactionmixtures. The activator (MMAO-3A as a 50 mM solution inmethylcyclohexane) was added first to the glass inserts. The precatalystwas then added to the glass insert as a precatalyst solution comprisingthe ligating compound and chromium source of the catalyst system inchlorobenzene. The ligating compound and chromium source were selectedeither from the preformed ligating compound-chromium complexes of theabove working examples or from the ligating compounds of the aboveworking examples combined with a selected chromium source (in theseethylene oligomerization Examples, either CrCl₃(THF)₃ ortris(2,4-pentanedionato-O,O′)chromium, (Cr(acac)₃).

The in situ precatalyst solutions were prepared as follows: A 1 mMchlorobenzene solution of CrCl₃(THF)₃ or Cr(acac)₃ was combined with a 1mM chlorobenzene solution of the selected ligating compound in a 1:1.2ratio in 8-mL vials in a 24-sample plate (3×8). The samples were mixedfor 30 minutes on a shaker before transferring them to the appropriateglass inserts in the HOPR cells. Preformed ligating compound-chromiumcomplex solutions were prepared by mixing a preformed ligatingcompound-chromium complex prepared as shown in the above workingexamples (e.g., Ex 1, CEx A) in chlorobenzene to form 1 mM solutionsbefore transferring them to the appropriate glass inserts in the HOPRcells. For comparison, the N,N-bis(diphenylphosphino)-N-isopropylamineligating compound 100 was included in each library as a standard.Consistent activity and selectivity of this standard between librariesallowed for the catalysis results to be compared across libraries. Eachlibrary comprised twelve individual experiments designed to have theamount of chromium indicated at the bottom of each High-ThroughputOligomerization Results table present in 4 mL of total solution volume(with the exception that one library was run with a total solutionvolume of 5 mL), with a duplicate of each experiment, in each HOPR run.

Following the preparation of the reaction mixtures, the glass tubes weredistributed in a 3×8 configuration in the HOPR cells and the reactor wassealed. The cells were pressurized with 100 psi (0.689 megapascals(MPa)) of ethylene and heated to the desired temperature (45° C.), asmonitored by five thermocouples in the stainless steel block. Once thereaction temperature was reached, the cells were pressurized up to 500psi with ethylene. After 30 minutes, the reactions were terminated bystopping the ethylene feed and cooling to room temperature. The reactorwas slowly vented at room temperature in order to limit loss oflow-boiling analytes (e.g., 1-hexene). A liquid sample from each cellwas removed for gas chromatographic (GC) analysis, and the remainder ofthe liquid present was removed in vacuo on a Savant SC250EX Speed VacConcentrator (Thermo Fisher). The glass tubes were then weighed todetermine the amount of residual solids present. The residual solidspresent comprised any polymer which formed and catalyst system residues.At the activator to ligating compound+chromium source or activator toligating compound-chromium complex ratios used in the followingoligomerization examples, over 95% of the mass of the catalyst systemresidues arose from the MMAO-3A activator. Thus the weight of theresidual solids from a control experiment tube containing only MMAO-3Asolution is subtracted from the weight of the total residual solids inthe oligomerization reaction tubes to give a good approximation of theamount of polymer produced in each oligomerization reaction tube. Thechromium to activator (Cr:MMAO-3A) ratios and chromium loading levelsare shown beneath the tables of oligomerization results. A summary ofthe conditions for the high-throughput ethylene oligomerizationexperiments is given in Table 1.

TABLE 1 Summary of conditions for high-throughput ethyleneoligomerization experiments Parameter Value Chromium source CrCl₃(THF)₃Chromium source:ligating compound 1:1.2 Ethylene pressure 500 psiReaction temperature 45° C. Reaction time 30 minutes SolventMethylcyclohexane Activator 1000 equiv MMAO-3A; Source: AkzoNobel GCinternal standard 50 mg nonane

Activity and selectivity calculations include all major reactionproducts: 1-octene, 1-hexene, polymer, cyclic C6 products(methylcyclopentane and methylenecyclopentane), and higher C₁₀₋₁₈ olefinoligomers. The amounts of the cyclic products (methylcyclopentane andmethylenecyclopentane) and higher C₁₀₋₁₈ olefin oligomers werequantified to obtain complete mass balance, however, only the activitiesand selectivities for the main products of interest (1-octene, 1-hexene,polymer, and, for one set of results, higher C₁₀₋₁₈ olefin oligomers)for the high-throughput ethylene oligomerization experiments aresummarized in the High-Throughput Oligomerizarion Results tables below(see Table 4-9). The activity and selectivity values given here are theaverages of two replicates.

Batch Reactor Experimental Information

The ethylene oligomerization reactions were conducted in a 300-mL Parrbatch reactor equipped with a 10-mL catalyst shot tank and an agitator.The reactor was heated by an electrical resistive heating mantle andcooled by an internal cooling coil. Both the reactor and thetemperature-control system were controlled and monitored by a Camile TGautomation system.

All reactor manipulations and solution preparations were performed in anitrogen-purged glovebox. For precatalysts prepared in situ, a solutionof 1.2 equiv of the selected ligating compound in methylcyclohexane (2mM) was added in a dropwise fashion to a solution of 1 equiv of the Crprecursor in chlorobenzene (2 mM), and the resulting solution wasstirred for 30 minutes. For precatalysts comprising preformed ligatingcompound-chromium complexes, a solution of the selected preformedligating compound-chromium complex was prepared in chlorobenzene (2 mM).Methylcyclohexane (100 mL) was added to the reactor body in a glovebox,along with MMAO-3A (1.77 M in heptane) and nonane, which served as theinternal standard for GC analysis. The precatalyst solution was loadedinto a 10-mL catalyst shot tank. Residual precatalyst solution in thevial and syringes used to handle the precatalyst solution was rinsedwith 2.5 mL of methylcyclohexane into the shot tank. The reactor wassealed and removed from the glovebox.

The reactor was then transferred to a reactor stand with the heatingmantle, and connections were made to the nitrogen and ethylene feedlines, cooling lines, a knockout pot, and a vent line. The agitator wasturned on. The knockout pot was then purged with nitrogen for fiveminutes while the reactor was pressure tested to 750 psi (5.17 MPa) withnitrogen. After the pressure test, the reactor was slowly vented toabout 10 psi (68.9 kilopascal (KPa)) and then slowly heated to 70° C.Once this temperature was reached, ethylene was added through a Brooksthermal mass flow meter to the desired reaction pressure. Once thereactor temperature and pressure stabilized, the catalyst shot tank waspressurized to 200 psi (1.38 MPa) over the reactor pressure withnitrogen, and the precatalyst solution was injected into the reactor,beginning the reaction. Ethylene was fed on demand through the Brooksthermal mass flow controller and the temperature was controlled byadjusting the mantle temperature and the flow through the internalcooling coil.

After the 30-minute reaction time, the ethylene feed was stopped and thereactor was cooled to 35° C., then vented at a rate of 1-4 psi(6.89-27.6 KPa) per second until 10 psi was reached. At this point, thereactor was returned to the nitrogen-filled glovebox where it wasopened. The reactor contents were sampled for GC analysis, then emptiedinto a pan. Any residual polymer remaining in the reactor was thoroughlycleaned out and added to the reactor contents in the pan. The bulk ofthe solvent was allowed to evaporate off and the residual solids weredried in a vacuum oven. The resulting polymer residue was weighed togive the polymer yield for the reaction.

Activity and selectivity calculations include all major reactionproducts: 1-octene, 1-hexene, polymer, cyclic C6 products(methylcyclopentane and methylenecyclopentane), and higher C₁₀₋₁₈ olefinoligomers. The amounts of the cyclic products (methylcyclopentane andmethylenecyclopentane) and higher C₁₀₋₁₈ olefin oligomers werequantified to obtain complete mass balance, however, only the activitiesand selectivities for the main products of interest (1-octene, 1-hexene,and polymer) for the batch reactor ethylene oligomerization experimentsare summarized in the Batch Reactor Oligomerization Results tables below(see Tables 10-12). Unless otherwise indicated, the activity andselectivity values given were obtained from single runs (not averagedfrom multiple runs)

Analytical Procedures

The liquid reaction products were analyzed on an Agilent 7890 GC System.The GC conditions for the Agilent 7890 system are listed in Table 2below.

TABLE 2 GC conditions GC Agilent 7890 Series Column Agilent (DB-5MS), 30m × 32 μm, 1 μm film Oven 70° C. for 8 min, ramp 50° C./min to 300° C.(hold 3.4 min) Total time-16 min Inlet 300° C., Split, 30:1 split ratioCarrier Gas Hydrogen, 1.33 mL/min constant flow Flame Ionization 320°C., 45 mL/min H₂, 450 mL/min air Detector Injection Volume 1 μL,chlorobenzene wash solvent

Samples for GC analysis for the high-throughput and batch reactorexperiments were prepared by quenching 75 μL of the reaction mixturewith 25 μL of methanol. The response factors were determined for1-octene, 1-hexene, methylcyclopentane, and methylenecyclopentane bycalibration using a standard solution with known concentrations. Theresponse factors used for the C10 to C18 fractions were determined usingthe terminal olefins of the same carbon length (e.g., 1-decene for theC10 fraction). The GC retention times for the C10-C18 olefins used asstandards are given in Table 3. The concentrations of the reactionproducts were reported by the GC instrument on a g/(g nonane) basisbecause nonane was included as an internal standard at a knownconcentration in the reaction tubes. The amounts of the various reactionproducts produced were calculated relative to the amount of nonane addedto the reaction mixture.

Activity, defined as the ratio of the amount of a selected productobtained from a given run to the amount of chromium used in the givenrun divided by the length of the given run in hours, is calculated for agiven run by obtaining the ratio of the amount in grams of a selectedreaction product (e.g., 1-octene, 1-hexene, polymer, cyclics, C₁₀₋₁₈oligomers, total of all products) from the given run to the amount ingrams of chromium used in the given run and dividing that ratio by thetime of the given run in hours. Selectivity, defined as the ratio of theamount of a selected product obtained from a given run to the totalamount of all products from the given run, is calculated for a given runby obtaining the ratio of the amount in grams of a selected reactionproduct (e.g., 1-octene, 1-hexene, polymer, cyclics, C₁₀₋₁₈ oligomers)to the total amount in grams of all products from the given run. Theterm “all products” with respect to the activity and the selectivitymeans the sum of the 1-octene, 1-hexene, polymer, cyclics, and C₁₀₋₁₈oligomers.

TABLE 3 Retention times for C10-C18 olefins. Product Retention time(min) Decenes 10.00-11.00 Dodecenes 11.30-11.80 Tetradecenes 11.81-12.70Hexadecenes 13.00-13.50 Octadecenes 13.70-14.20

TABLE 4 High-Throughput Oligomerization Results - in situ catalystformation* Ligating Activity (g/g Cr h) Selectivity (wt %) Examplecompound 1-Octene 1-Hexene Polymer Total 1-Octene 1-Hexene Polymer 1 1001,220,000 205,000 26,000 1,451,000 74.1 12.6 1.52 2 553 4,665,0001,391,000 28,000 6,084,000 67.1 20.0 0.39 3 565 937,000 758,000 19,0001,714,000 48.2 39.0 0.91 4 592 5,802,000 3,104,000 28,000 8,934,000 58.730.8 0.30 5 594 4,780,000 3,047,000 30,000 7,857,000 54.9 34.4 0.36 6601 6,364,000 5,130,000 29,000 11,523,000 50.9 40.4 0.25 7 603 6,878,0004,508,000 33,000 11,419,000 53.6 35.2 0.26 8 604 8,857,000 5,072,00058,000 13,987,000 57.9 33.2 0.38 9 606 4,406,000 1,860,000 27,0006,293,000 63.1 26.5 0.38 10 607 1,334,000 990,000 29,000 2,353,000 52.637.3 1.31 11 608 4,446,000 2,618,000 25,000 7,089,000 56.7 33.4 0.31 12613 4,265,000 1,149,000 19,000 5,433,000 72.3 19.5 0.32 13 615 1,600,000553,000 77,000 2,230,000 62.0 21.3 3.02 14 618 3,380,000 1,051,00020,000 4,451,000 68.1 21.2 0.39 15 619 1,694,000 1,190,000 17,0002,901,000 53.9 38.1 0.54 16 620 888,000 1,113,000 6,000 2,007,000 40.050.0 0.29 17 627 1,018,000 3,302,000 45,000 4,365,000 22.2 71.8 0.91 18628 1,681,000 629,000 53,000 2,363,000 62.4 23.4 1.96 19 629 3,841,000888,000 22,000 4,751,000 77.0 17.8 0.45 20 630 4,952,000 1,988,00018,000 6,958,000 68.1 27.3 0.24 21 636 834,000 2,965,000 74,0003,873,000 20.8 73.3 1.85 22 637 864,000 1,307,000 22,000 2,193,000 36.855.4 0.98 23 638 6,672,000 4,272,000 109,000 11,053,000 55.1 34.7 0.9424 645 4,171,000 1,662,000 24,000 5,857,000 65.1 26.0 0.37 25 6474,303,000 2,098,000 25,000 6,426,000 60.1 29.3 0.35 26 648 4,617,0002,895,000 31,000 7,543,000 55.7 34.6 0.38 27 651 8,553,000 3,603,00051,000 12,207,000 64.8 27.3 0.39 28 652 5,485,000 3,426,000 26,0008,937,000 58.0 36.2 0.27 29 653 5,811,000 2,610,000 29,000 8,450,00059.8 26.7 0.28 30 654 2,480,000 1,867,000 27,000 4,374,000 53.1 40.00.61 31 664 3,030,000 1,355,000 130,000 4,515,000 61.4 27.4 2.62 32 6652,793,000 762,000 14,000 3,569,000 68.4 18.6 0.32 33 699 389,0001,450,000 43000 1,882,000 19.3 71.9 2.11 *Oligomerization Conditions:45° C.; 500 psi ethylene; Cr:MMAO-3A = 1:1000; run time = 50 minutes;chromium source: CrCl₃(THF)₃; chromium loading level: 0.008 μmol

TABLE 5 High-Throughput Oligomerization Results - preformed complexes asprecatalysts* Ligating compound or ligating compound- Activity (g/g Crh) Selectivity (wt %) Example chromium complex 1-Octene 1-Hexene PolymerTotal 1-Octene 1-Hexene Polymer 34 100 1,220,000 205,000 26,0001,451,000 74.1 12.6 1.52 35 403 177,000 1,000,000 15,000 1,192,000 13.475.6 1.19 36 421 291,000 123,000 10,000 424,000 55.2 23.3 1.55 37 422160,000 931,000 14,000 1,105,000 13.4 77.7 1.18 38 560 5,362,0001,898,000 50,000 7,310,000 64.7 22.9 0.60 *Oligomerization Conditions:45° C.; 500 psi ethylene; Cr:MMAO-3A = 1:1000; run time = 30 minutes;chromium source for Example 100: CrCl₃(THF)₃; chromium loading level:0.008 μmol.

TABLE 6 High-Throughput Oligomerizadon Results - preformed complexes asprecatalysts* Ligating compound or ligating compound- Activity (g/g Crh) Selectivity (wt %) Example chromium complex 1-Octene 1-Hexene PolymerTotal 1-Octene 1-Hexene Polymer 39 100 511,000 107,000 13,000 631,00069.94 14.67 1.76 40 421 305,000 148,000 8,000 461,000 52.56 25.46 1.3341 422 121,000 958,000 6,000 1,085,000 10.10 79.46 0.50 42 455 68,000232,000 6,000 306,000 19.85 68.14 1.69 *Oligomerization Conditions: 45°C.; 500 psi ethylene; Cr:MMAO-3A = 1:1000; run time = 30 minutes;chromium source for Example 100: CrCl₃(THF)₃; chromium loading level:0.05 μmol

TABLE 7 High-Throughput Oligomerization Results - preformed complexes asprecatalysts* Ligating compound or ligating compound- Activity (g/g Crh) Selectivity (wt %) Example chromium complex 1-Octene 1-Hexene PolymerTotal 1-Octene 1-Hexene Polymer 43 100 297,000 64,000 10,000 371,00069.2 15.0 2.30 44 372 172,000 58,000 6,000 236,000 56.0 18.8 2.09 45 40391,000 777,000 5,000 873,000 9.19 78.2 0.46 46 421 264,000 154,000 6,000424,000 49.6 28.8 1.07 47 422 68,000 495,000 6,000 569,000 10.8 78.70.88 48 596 18,000 809,000 57,000 884,000 1.98 86.2 5.32*Oligomerization Conditions: 45° C.; 500 psi ethylene; Cr:MMAO-3A =1:1000; run time = 30 minutes; chromium source for Example 100:CrCl₃(THF)₃; chromium loading level: 0.1 μmol

TABLE 8 High-Throughput Oligomerization Results - Comparative Examples*Ligating compound or ligating compound- Activity (g/g Cr h) Selectivity(wt %) Example chromium complex 1-Octene 1-Hexene Polymer Total 1-Octene1-Hexene Polymer C1 100 278,000 72,000 8,000 358,000 73.2 19.0 2.0 C2404 368,000 95,000 13,000 477,000 72.6 18.8 2.6 C3 430 21,000 21,00015,000 57,000 32.8 32.9 22.8 C4 431 2,000 3,000 1,000 6,000 24.4 41.420.3 C5 453 9,000 6,000 4,000 19,000 31.8 22.7 13.7 *OligomerizationConditions: 45° C.; 500 psi ethylene; Cr:MMAO-3A = 1:1000; run time = 30minutes; chromium source for Example 100: CrCl₃(THF)₃; chromium loadinglevel: 0.1 μmol; total volume 5 mL

TABLE 9 High-Throughput Oligomerization Results - in situ catalystformation* C10-C18 Ligating Total Activity Selectivity Example compound(g/g Cr h) (wt %) 49 100 1,451,000 6.38 50 594 7,857,000 5.45 51 60111,523,000 3.45 52 603 11,419,000 4.38 53 607 2,353,000 2.80 54 6135,433,000 4.68 55 615 2,230,000 6.07 56 620 2,007,000 2.84 57 6274,365,000 4.58 58 629 4,751,000 3.47 59 630 6,958,000 3.50 60 6363,873,000 3.47 61 637 2,193,000 4.25 62 651 12,207,000 6.11 63 6528,937,000 4.59 64 654 4,374,000 4.24 *Oligomerization Conditions: 45°C.; 500 psi ethylene; Cr:MMAO-3A = 1:1000; run time = 30 minutes;chromium source: CrCl₃(THF)₃; chromium loading level: 0.008 μmol

TABLE 10 Batch Reactor Oligomerization Results* Ligating compound orligating compound- Activity (g/g Cr h) Selectivity (wt %) Examplechromium complex 1-Octene 1-Hexene Polymer Total 1-Octene 1-HexenePolymer 65 100** 747,000 230,198 14,508 991,706 68.6 21.2 1.3 66 404**792,440 252,358 21,138 1,065,936 68.1 21.7 1.8 67 372** 501,461 273,2549,200 783,915 54.8 29.9 1.0 68 403^(†)  342,991 1,657,579 12,2122,012,782 16.0 77.1 0.6 69 553^(†)  3,399,495 1,487,577 16,615 4,903,68764.0 28.0 0.3 70 560^(†)  3,864,789 1,783,422 24,981 5,673,192 62.4 28.80.4 *Oligomerization Conditions: 70° C.; 700 psi ethylene; Cr:MMAO-3A =1:1000; run time = 30 minutes; chromium source for Examples 100 and 553:CrCl₃(THF)₃ **Chromium loading level: 0.05 μmol ^(†)Chromium loadinglevel: 0.2 μmol

TABLE 11 Batch Reactor Oligomerization Results with Cr(acac)₃* LigatingActivity (g/g Cr h) Selectivity (wt %) Example compound 1-Octene1-Hexene Polymer Total 1-Octene 1-Hexene Polymer 71 100** 742,000242,000 16,000 1,000,000 67.2 22.2 1.60 72 553^(†)  2,404,000 1,129,00020,000 3,553,000 61.6 29.0 0.57 *Oligomerization Conditions: 70° C.; 700psi ethylene; Cr:MMAO-3A = 1:1000; run time = 30 minutes; chromiumsource: Cr(acac)₃; catalyst loading = 0.2 μmol **Average of three runsin the batch reactor at the given conditions ^(†)Average of eight runsin the batch reactor at the given conditions

TABLE 12 Batch Reactor Oligomerization Results with Varying ChromiumConcentrations and Cr:MMAO ratios* Ligating [Al] [Cr] Activity (g/g Crh) Selectivity (wt %) Example compound (mM) (μM) 1-Octene 1-HexenePolymer Total 1-Octene 1-Hexene Polymer 72 553^(‡) 1.0 1.0** 2,871,0001,334,000 48,000 4,253,000 62.5 29.0 1.02 73 100^(‡) 577,000 189,00029,000 795,000 68.1 22.3 3.45 74 553^(‡) 2.0^(†) 1,917,000 903,00020,000 2,840,000 62.0 29.2 0.65 75 100^(∥ ) 553,000 183,000 57,000793,000 63.8 21.1 6.63 76  553^(††) 2.0 2.0** 2,404,000 1,129,000 20,0003,553,000 61.6 29.6 0.57 77 100^(∥ ) 742,000 242,000 16,000 1,000,00067.2 22.2 1.60 78 553^(∥ ) 4.0^(†) 2,841,000 1,487,000 19,000 4,347,00057.9 30.2 0.45 79 100^(‡) 1,089,000 364,000 18,000 1,471,000 66.4 22.21.10 80 553^(‡) 3.0 3.0** 1,914,000 910,000 22,000 2,846,000 61.1 29.00.69 81 100^(‡) 842,000 276,000 20,000 1,138,000 67.2 21.9 1.65 82553^(‡) 6.0^(†) 1,475,000 712,000 56,000 2,243,000 59.1 28.5 2.25 83100^(‡) 559,000 177,000 22,000 758,000 67.2 21.4 2.67 *OligomerizationConditions: 70° C.; 700 psi ethylene; run time = 30 minutes; chromiumsource: Cr(acac)₃ **Cr:MMAO-3A = 1:1000 ^(†)Cr:MMAO-3A = 1:500^(‡)Average of two runs in the batch reactor at the given conditions^(∥)Average of three runs in the batch reactor at the given conditions^(††)Average of seven runs in the batch reactor at the given conditions

1. A composition comprising a phosphacycle-containing ligating compoundrepresented as:

wherein: P is phosphorus; X₁ is selected from nitrogen, phosphorus,oxygen, or sulfur; each of R₁ and R₂ is independently a substituted orunsubstituted hydrocarbon derivative, a substituted or unsubstitutedheterohydrocarbon derivative, or a substituted or unsubstitutedheteroatom group having from one to 50 non-hydrogen atoms; m is 0 or 1;R₁ and R₂ are linked together to form a divalent moiety represented as

 which together with P forms a cyclic structure (phosphacycle)containing from 3 to 10 ring atoms; each of R₃ and R₄ is independentlyhydrogen, halogen, a substituted or unsubstituted hydrocarbonderivative, a substituted or unsubstituted heterohydrocarbon derivative,or a substituted or unsubstituted heteroatom group having from one to 50non-hydrogen atoms; R₃ and R₄ are optionally linked together to form adivalent moiety represented as

 wherein the optional character of the linkage is depicted by a dashedconnection, which together with X₁ forms a cyclic structure containingfrom 3 to 10 ring atoms; Y, optionally linked together with one or moreof R₁, R₂, R₃, or R₄ to form cyclic structures containing from 4 to 10ring atoms, as represented by:

wherein the optional character of the linkages is depicted by a dashedconnection, is a divalent linking group [L(R₅)_(q)]_(p) between P and X₁containing from one to 50 non-hydrogen atoms; [L(R₅)_(q)]_(p) isrepresented by:

wherein each L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur; p is an integer number from 1 to 6; R₅ is independentlyhydrogen, halogen, substituted or unsubstituted hydrocarbon derivative,substituted or unsubstituted heterohydrocarbon derivative, or asubstituted or unsubstituted heteroatom group; q is 0, 1, or 2; providedthat the [L]_(p) subunit of the divalent linking group [L(R₅)_(q)]_(p)does not comprise an amidine (N—C═N) group; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; still furtherprovided that one or two phosphacycles comprising P, R₁, and R₂, orcomprising X₁, R₃, and R₄, contain no P—N, P—O, or P—S bonds within thering part of the phosphacycle; two or more R₅ groups independently arelinked together with at least one L atom to form a cyclic structure thatcontains from 3 to 10 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms; from two to ten independently selectedligating compounds may be optionally linked together via theirrespective independently selected Y, R₁, R₂, R₃, R₄ or R₅ groups to forma poly(ligating compound) species, and wherein the composition is not8-aza-1-phosphatricylo[3.3.0.0^(2,6)]octane.
 2. The composition of claim1, wherein the phosphacycle-containing ligating compound is representedas:

wherein q of C(R₅)_(q) is 1 or 2 and q of L(R₅)_(q) is 0, 1 or 2;[L(R₅)_(q)] of the phosphacycles is C(R₅), N, N(R₅), or C(R₅)₂; theC(R₅)_(q) attached to P is C(R₅), C(R₅)₂, or C(R₅)H; two or more R₃, R₄or R₅ groups are optionally linked together to form cyclic structurescontaining from 4 to 10 ring atoms; two or more R₅ groups independentlyare linked together with at least one L atom to form a cyclic structurethat contains from 3 to 10 ring atoms; two R₅ groups attached to thesame L atom may be optionally linked together to form a cyclic structurethat contains from 3 to 10 ring atoms; optionally from two to tenindependently selected ligating compounds may be linked together viatheir respective independently selected R₃, R₄ or R₅ groups to form apoly(ligating compound) species.
 3. The composition of claim 1, whereinthe phosphacycle-containing ligating compound is selected from the groupconsisting of:


4. A composition represented as

wherein L is independently selected from the group consisting of boron,carbon, silicon, germanium, nitrogen, phosphorus, oxygen, and sulfur; pis an integer number from 1 to 6; R₅ is independently hydrogen, halogen,substituted or unsubstituted hydrocarbon derivative, substituted orunsubstituted heterohydrocarbon derivative, or a substituted orunsubstituted heteroatom group; q is 0, 1, or 2; R′ independentlyselected is hydrogen, C₁₋₂₀ hydrocarbyl, C₁₋₂₀ heterohydrocarbyl orhalide; and wherein the composition is not8-aza-1-phosphatricylo[3.3.0.0^(2,6)]octane.
 5. A process to prepare acomposition comprising a phosphacycle-containing ligating compoundrepresented as:

wherein: P is phosphorus; X₁ is selected from nitrogen, phosphorus,oxygen, or sulfur; each of R₁ and R₂ is independently a substituted orunsubstituted hydrocarbon derivative, a substituted or unsubstitutedheterohydrocarbon derivative, or a substituted or unsubstitutedheteroatom group having from one to 50 non-hydrogen atoms; m is 0 or 1;R₁ and R₂ are linked together to form a divalent moiety represented as

 which together with P forms a cyclic structure (phosphacycle)containing from 3 to 10 ring atoms; each of R₃ and R₄ is independentlyhydrogen, halogen, a substituted or unsubstituted hydrocarbonderivative, a substituted or unsubstituted heterohydrocarbon derivative,or a substituted or unsubstituted heteroatom group having from one to 50non-hydrogen atoms; R₃ and R₄ are optionally linked together to form adivalent moiety represented as

 wherein the optional character of the linkage is depicted by a dashedconnection, which together with X₁ forms a cyclic structure containingfrom 3 to 10 ring atoms; Y, optionally linked together with one or moreof R₁, R₂, R₃, or R₄ to form cyclic structures containing from 4 to 10ring atoms, as represented by:

wherein the optional character of the linkages is depicted by a dashedconnection, is a divalent linking group [L(R₅)_(q)]_(p) between P and X₁containing from one to 50 non-hydrogen atoms; [L(R₅)_(q)]_(p) isrepresented by:

wherein each L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur; p is an integer number from 1 to 6; R₅ is independentlyhydrogen, halogen, substituted or unsubstituted hydrocarbon derivative,substituted or unsubstituted heterohydrocarbon derivative, or asubstituted or unsubstituted heteroatom group; q is 0, 1, or 2; providedthat the [L]_(p) subunit of the divalent linking group [L(R₅)_(q)]_(p)does not comprise an amidine (N—C═N) group; further provided that in atleast one phosphacycle of the phosphacycle-containing ligating compound,both atoms directly bonded to P or X₁ are sp³ hybridized; still furtherprovided that one or two phosphacycles comprising P, R₁, and R₂, orcomprising X₁, R₃, and R₄, contain no P—N, P—O, or P—S bonds within thering part of the phosphacycle; two or more R₅ groups independently arelinked together with at least one L atom to form a cyclic structure thatcontains from 3 to 10 ring atoms; two R₅ groups attached to the same Latom may be optionally linked together to form a cyclic structure thatcontains from 3 to 10 ring atoms; from two to ten independently selectedligating compounds may be optionally linked together via theirrespective independently selected Y, R₁, R₂, R₃, R₄ or R₅ groups to forma poly(ligating compound) species, the steps of the process comprising:a) contacting approximately one equivalent of

 or silyl derivative thereof, represented as

 with approximately one equivalent of a

 cyclic or acyclic precursor, or b) contacting approximately oneequivalent of

 or silyl derivative thereof, represented as

 with approximately one equivalent of a

 cyclic precursor; optionally in the presence of at least one equivalentof a proton scavenger; X is a leaving group; R′ independently selectedis hydrogen, C₁₋₆ hydrocarbyl, or halide; and optionally isolating theproduct.
 6. The process of claim 5 wherein X is halide.
 7. The processof claim 5, wherein at least five equivalents of a proton scavenger areused.
 8. The process of claim 5, wherein

are represented as


9. A process wherein a cyclic phosphine halide represented as:

is prepared in one chemical step represented as:

wherein the structure:

represents an intermediate cyclic phosphinic amide, the step comprising:contacting the intermediate cyclic phosphinic amide with at least onehydrido-silicon compound represented as R′₃SiH and at least one siliconhalide compound represented as R′₃SiX in the presence of one or morebases, wherein L is independently selected from the group consisting ofboron, carbon, silicon, germanium, nitrogen, phosphorus, oxygen, andsulfur; R₅ is independently hydrogen, halogen, substituted orunsubstituted hydrocarbon derivative, substituted or unsubstitutedheterohydrocarbon derivative, or a substituted or unsubstitutedheteroatom group; t is 1, 2, 3, or 4; R″ independently selected ishydrogen or C₁₋₂₀ hydrocarbon derivative; R′ independently selected ishydrogen, C₁₋₂₀ hydrocarbyl, C₁₋₂₀ heterohydrocarbyl or halide; X ischloride, bromide, iodide; each base of the one or more bases isindependently a hydrocarbylamine.
 10. The process as in claim 9, whereinthe cyclic phosphine halide is represented as

wherein L is carbon or nitrogen; and, X is chloride or iodide.